lvalue required as left operand of assignment exit status 1

Solve error: lvalue required as left operand of assignment

In this tutorial you will know about one of the most occurred error in C and C++ programming, i.e. lvalue required as left operand of assignment.

lvalue means left side value. Particularly it is left side value of an assignment operator.

rvalue means right side value. Particularly it is right side value or expression of an assignment operator.

In above example a is lvalue and b + 5 is rvalue.

In C language lvalue appears mainly at four cases as mentioned below:

Left of assignment operator.
Left of member access (dot) operator (for structure and unions).
Right of address-of operator (except for register and bit field lvalue).
As operand to pre/post increment or decrement for integer lvalues including Boolean and enums.

Now let see some cases where this error occur with code.

When you will try to run above code, you will get following error.

Solution: In if condition change assignment operator to comparison operator, as shown below.

Above code will show the error: lvalue required as left operand of assignment operator.

Here problem occurred due to wrong handling of short hand operator (*=) in findFact() function.

Solution : Just by changing the line ans*i=ans to ans*=i we can avoid that error. Here short hand operator expands like this, ans=ans*i. Here left side some variable is there to store result. But in our program ans*i is at left hand side. It’s an expression which produces some result. While using assignment operator we can’t use an expression as lvalue.

The correct code is shown below.

Above code will show the same lvalue required error.

Reason and Solution: Ternary operator produces some result, it never assign values inside operation. It is same as a function which has return type. So there should be something to be assigned but unlike inside operator.

The correct code is given below.

Some Precautions To Avoid This Error

There are no particular precautions for this. Just look into your code where problem occurred, like some above cases and modify the code according to that.

Mostly 90% of this error occurs when we do mistake in comparison and assignment operations. When using pointers also we should careful about this error. And there are some rare reasons like short hand operators and ternary operators like above mentioned. We can easily rectify this error by finding the line number in compiler, where it shows error: lvalue required as left operand of assignment.

Programming Assignment Help on Assigncode.com, that provides homework ecxellence in every technical assignment.

Comment below if you have any queries related to above tutorial.

Basic structure of c program, introduction to c programming language, variables, constants and keywords in c, first c program – print hello world message, 6 thoughts on “solve error: lvalue required as left operand of assignment”.

hi sir , i am andalib can you plz send compiler of c++.

i want the solution by char data type for this error

#include #include #include using namespace std; #define pi 3.14 int main() { float a; float r=4.5,h=1.5; {

a=2*pi*r*h=1.5 + 2*pi*pow(r,2); } cout<<" area="<<a<<endl; return 0; } what's the problem over here

#include using namespace std; #define pi 3.14 int main() { float a,p; float r=4.5,h=1.5; p=2*pi*r*h; a=1.5 + 2*pi*pow(r,2);

cout<<" area="<<a<<endl; cout<<" perimeter="<<p<<endl; return 0; }

You can't assign two values at a single place. Instead solve them differetly

Hi. I am trying to get a double as a string as efficiently as possible. I get that error for the final line on this code. double x = 145.6; int size = sizeof(x); char str[size]; &str = &x; Is there a possible way of getting the string pointing at the same part of the RAM as the double?

Lvalue Required as Left Operand of Assignment: What It Means and How to Fix It

Lvalue Required as Left Operand of Assignment

Have you ever tried to assign a value to a variable and received an error message like “lvalue required as left operand of assignment”? If so, you’re not alone. This error is a common one, and it can be frustrating to figure out what it means.

In this article, we’ll take a look at what an lvalue is, why it’s required as the left operand of an assignment, and how to fix this error. We’ll also provide some examples to help you understand the concept of lvalues.

So if you’re ever stuck with this error, don’t worry – we’re here to help!

Column 1	Column 2	Column 3
Lvalue	A variable or expression that can be assigned a value	Required as the left operand of an assignment operator
Example	x = 5	The variable `x` is the lvalue and the value `5` is the rvalue
Error	>>> x = y TypeError: lvalue required as left operand of assignment	The error occurs because the variable `y` is not a lvalue

In this tutorial, we will discuss what an lvalue is and why it is required as the left operand of an assignment operator. We will also provide some examples of lvalues and how they can be used.

What is an lvalue?

An lvalue is an expression that refers to a memory location. In other words, an lvalue is an expression that can be assigned a value. For example, the following expressions are all lvalues:

int x = 10; char c = ‘a’; float f = 3.14;

The first expression, `int x = 10;`, defines a variable named `x` and assigns it the value of 10. The second expression, `char c = ‘a’;`, defines a variable named `c` and assigns it the value of the character `a`. The third expression, `float f = 3.14;`, defines a variable named `f` and assigns it the value of 3.14.

Why is an lvalue required as the left operand of an assignment?

The left operand of an assignment operator must be a modifiable lvalue. This is because the assignment operator assigns the value of the right operand to the lvalue on the left. If the lvalue is not modifiable, then the assignment operator will not be able to change its value.

For example, the following code will not compile:

int x = 10; const int y = x; y = 20; // Error: assignment of read-only variable

The error message is telling us that the variable `y` is const, which means that it is not modifiable. Therefore, we cannot assign a new value to it.

Examples of lvalues

Here are some examples of lvalues:

Variable names: `x`, `y`, `z`
Arrays: `a[0]`, `b[10]`, `c[20]`
Pointers: `&x`, `&y`, `&z`
Function calls: `printf()`, `scanf()`, `strlen()`
Constants: `10`, `20`, `3.14`

In this tutorial, we have discussed what an lvalue is and why it is required as the left operand of an assignment operator. We have also provided some examples of lvalues.

I hope this tutorial has been helpful. If you have any questions, please feel free to ask in the comments below.

3. How to identify an lvalue?

An lvalue can be identified by its syntax. Lvalues are always preceded by an ampersand (&). For example, the following expressions are all lvalues:

4. Common mistakes with lvalues

One common mistake is to try to assign a value to an rvalue. For example, the following code will not compile:

int x = 5; int y = x = 10;

This is because the expression `x = 10` is an rvalue, and rvalues cannot be used on the left-hand side of an assignment operator.

Another common mistake is to forget to use the ampersand (&) when referring to an lvalue. For example, the following code will not compile:

int x = 5; *y = x;

This is because the expression `y = x` is not a valid lvalue.

Finally, it is important to be aware of the difference between lvalues and rvalues. Lvalues can be used on the left-hand side of an assignment operator, while rvalues cannot.

In this article, we have discussed the lvalue required as left operand of assignment error. We have also provided some tips on how to identify and avoid this error. If you are still having trouble with this error, you can consult with a C++ expert for help.

Q: What does “lvalue required as left operand of assignment” mean?

A: An lvalue is an expression that refers to a memory location. When you assign a value to an lvalue, you are storing the value in that memory location. For example, the expression `x = 5` assigns the value `5` to the variable `x`.

The error “lvalue required as left operand of assignment” occurs when you try to assign a value to an expression that is not an lvalue. For example, the expression `5 = x` is not valid because the number `5` is not an lvalue.

Q: How can I fix the error “lvalue required as left operand of assignment”?

A: There are a few ways to fix this error.

Make sure the expression on the left side of the assignment operator is an lvalue. For example, you can change the expression `5 = x` to `x = 5`.
Use the `&` operator to create an lvalue from a rvalue. For example, you can change the expression `5 = x` to `x = &5`.
Use the `()` operator to call a function and return the value of the function call. For example, you can change the expression `5 = x` to `x = f()`, where `f()` is a function that returns a value.

Q: What are some common causes of the error “lvalue required as left operand of assignment”?

A: There are a few common causes of this error.

Using a literal value on the left side of the assignment operator. For example, the expression `5 = x` is not valid because the number `5` is not an lvalue.
Using a rvalue reference on the left side of the assignment operator. For example, the expression `&x = 5` is not valid because the rvalue reference `&x` cannot be assigned to.
Using a function call on the left side of the assignment operator. For example, the expression `f() = x` is not valid because the function call `f()` returns a value, not an lvalue.

Q: What are some tips for avoiding the error “lvalue required as left operand of assignment”?

A: Here are a few tips for avoiding this error:

Always make sure the expression on the left side of the assignment operator is an lvalue. This means that the expression should refer to a memory location where a value can be stored.
Use the `&` operator to create an lvalue from a rvalue. This is useful when you need to assign a value to a variable that is declared as a reference.
Use the `()` operator to call a function and return the value of the function call. This is useful when you need to assign the return value of a function to a variable.

By following these tips, you can avoid the error “lvalue required as left operand of assignment” and ensure that your code is correct.

In this article, we discussed the lvalue required as left operand of assignment error. We learned that an lvalue is an expression that refers to a specific object, while an rvalue is an expression that does not refer to a specific object. We also saw that the lvalue required as left operand of assignment error occurs when you try to assign a value to an rvalue. To avoid this error, you can use the following techniques:

Use the `const` keyword to make an rvalue into an lvalue.
Use the `&` operator to create a reference to an rvalue.
Use the `std::move()` function to move an rvalue into an lvalue.

We hope this article has been helpful. Please let us know if you have any questions.

Author Profile

Latest entries

December 26, 2023 Error Fixing User: Anonymous is not authorized to perform: execute-api:invoke on resource: How to fix this error
December 26, 2023 How To Guides Valid Intents Must Be Provided for the Client: Why It’s Important and How to Do It
December 26, 2023 Error Fixing How to Fix the The Root Filesystem Requires a Manual fsck Error
December 26, 2023 Troubleshooting How to Fix the `sed unterminated s` Command

Object is Possibly ‘null’ in TypeScript: What It Means and How to Fix It

Object is Possibly ‘Null’ in TypeScript In TypeScript, the `object is possibly ‘null’` error occurs when you try to access a property of an object that may not exist. This can happen when you’re using an object literal or when you’re dereferencing a variable that may be null. To avoid this error, you can use…

Unexpected Lexical Declaration in Case Block: What It Is and How to Fix It

Unexpected Lexical Declaration in Case Block The JavaScript language is full of quirks and gotchas, and one of the most common is the unexpected lexical declaration in a case block. This error occurs when you try to declare a variable inside a switch statement’s case block, but the variable has already been declared outside of…

No Incoming Connections Deluge: What It Is and How to Fix It

No Incoming Connections Deluge: What It Is and How to Prevent It In today’s interconnected world, it’s more important than ever to protect your network from incoming connections. A “no incoming connections deluge” is a denial-of-service (DoS) attack that floods your network with so many connection requests that it becomes impossible for legitimate traffic to…

Buffer is not defined in React: How to Fix

Buffer is not defined in React: A Comprehensive Guide If you’re a React developer, you’ve probably encountered the dreaded “buffer is not defined” error at some point. This error can be caused by a number of different factors, but it’s often due to a misunderstanding of how buffers work in React. In this comprehensive guide,…

How to Fix a Leaking Cast Iron Toilet Flange

How to Fix a Cast Iron Toilet Flange A cast iron toilet flange is a critical part of your toilet. It connects the toilet to the drainpipe and helps to keep water from leaking out. Over time, the flange can become damaged or worn out, which can lead to leaks and other problems. If you…

Resolving 'lvalue Required: Left Operand Assignment' Error in C++

Understanding and Resolving the 'lvalue Required: Left Operand Assignment' Error in C++

Abstract: In C++ programming, the 'lvalue Required: Left Operator Assignment' error occurs when assigning a value to an rvalue. In this article, we'll discuss the error in detail, provide examples, and discuss possible solutions.

Understanding and Resolving the "lvalue Required Left Operand Assignment" Error in C++

In C++ programming, one of the most common errors that beginners encounter is the "lvalue required as left operand of assignment" error. This error occurs when the programmer tries to assign a value to an rvalue, which is not allowed in C++. In this article, we will discuss the concept of lvalues and rvalues, the causes of this error, and how to resolve it.

Lvalues and Rvalues

In C++, expressions can be classified as lvalues or rvalues. An lvalue (short for "left-value") is an expression that refers to a memory location and can appear on the left side of an assignment. An rvalue (short for "right-value") is an expression that does not refer to a memory location and cannot appear on the left side of an assignment.

For example, consider the following code:

In this code, x is an lvalue because it refers to a memory location that stores the value 5. The expression x = 10 is also an lvalue because it assigns the value 10 to the memory location referred to by x . However, the expression 5 is an rvalue because it does not refer to a memory location.

Causes of the Error

The "lvalue required as left operand of assignment" error occurs when the programmer tries to assign a value to an rvalue. This is not allowed in C++ because rvalues do not have a memory location that can be modified. Here are some examples of code that would cause this error:

In each of these examples, the programmer is trying to assign a value to an rvalue, which is not allowed. The error message indicates that an lvalue is required as the left operand of the assignment operator ( = ).

Resolving the Error

To resolve the "lvalue required as left operand of assignment" error, the programmer must ensure that the left operand of the assignment operator is an lvalue. Here are some examples of how to fix the code that we saw earlier:

In each of these examples, we have ensured that the left operand of the assignment operator is an lvalue. This resolves the error and allows the program to compile and run correctly.

The "lvalue required as left operand of assignment" error is a common mistake that beginners make when learning C++. To avoid this error, it is important to understand the difference between lvalues and rvalues and to ensure that the left operand of the assignment operator is always an lvalue. By following these guidelines, you can write correct and efficient C++ code.

C++ Primer (5th Edition) by Stanley B. Lippman, Josée Lajoie, and Barbara E. Moo
C++ Programming: From Problem Analysis to Program Design (5th Edition) by D.S. Malik
"lvalue required as left operand of assignment" on cppreference.com

Learn how to resolve 'lvalue Required: Left Operand Assignment' error in C++ by understanding the concept of lvalues and rvalues and applying the appropriate solutions.

Accepting multiple positional arguments in bash/shell: a better way than passing empty arguments.

In this article, we will discuss a better way of handling multiple positional arguments in Bash/Shell scripts without passing empty arguments.

Summarizing Bird Detection Data with plyr in R

In this article, we explore how to summarize bird detection data using the plyr package in R. We will use a dataframe containing 11,000 rows of bird detections over the last 5 years, and we will apply various summary functions to extract meaningful insights from the data.

Tags: : C++ Programming Error Debugging

Latest news

Managing Config Variables in a Single .env File for C# Tests in VSCode
MySQL Workbench Accusing MariaDB Error on Foreign Key Installation
React-Vite Docker Error: Could not resolve entry module 'index.html'
Understanding Docker Isolation: Stage 1 vs Stage 2
Understanding Bitwise Operations in MATLAB for 2D to 1D Conversion via Hilbert Curve
Solving the Problem of Finding the First Value in a Segment Tree
Implementing a 'People May Know' Section in Your Social App: A Better Way
Top-Down Movement in Unity2D using RigidBodies: Player to Lily Pad Interaction
Issue Installing 32-bit Matplotlib in Python
Optimizing Memory Usage in Real-Time Data Processing with Python Pandas
Troubleshooting Hamburger Menu Implementation in Android Development
Setting User-Changed Variables in Python: Overwrite or Merge?
Adding a Consistent Footer to PDF Files in Software Development
Fixing Menu Glitches in Elementor v3.21: A Guide for Site Owners
Troubleshooting Expected Identifier Errors in BizTalk 2016 SFTP Integrations
Error: Item Key Already Added in HttpPost, setUSUARIO
Chasing Sand and Lizards: Weather Forecasts for Project Sites
Creating a Blazor Server App with DetailedErrors in Visual Studio
std::fstream::write() modifies tellg()?
Interacting with OllamaAPI: Handling Significant Response Messages
Implementing Recovery Codes in TOTP Multi-Factor Authentication: A Backup Solution
Errors Sending Request to API: Dolar Endpoint
Using LAG Function to Get Last 'Consume' Event in SQL for Product Units
Measuring Actual Indefiniteness: Understanding Undefined Behavior Memory Access in C's free() Call
Renaming Columns in Workbook View Control
Error in Reading Block 2 File during PostgreSQL Table Import
Custom Domain Blocked: Hosting Angular Application on GitHub Pages
Assigning Tasks with Google Forms: Performflow Integration
Writing OData Queries with Filter Property and Deep Expands
Making No One See Your Request Traffic with Python
NPMP Installation Taking Forever: Unable to Finish (Local PC and Docker)
Automating Birthday Wishes: Seeking Recommendations for a Free WhatsApp API
ImageField Django Forms Not Working: A Solution
Rules for Snake Wrestling Competition: Eligibility Criteria
Maintaining Unique Git Subtrees in Shopify: Best Practices

Troubleshooting 'error: lvalue required as left operand of assignment': Tips to Fix Assignment Errors in Your Code

Are you struggling with the "error: lvalue required as left operand of assignment" error in your code? Don't worry; this error is common among developers and can be fixed with a few simple tips. In this guide, we will walk you through the steps to troubleshoot and fix this error.

Understanding the Error

The "error: lvalue required as left operand of assignment" error occurs when you try to assign a value to a non-modifiable lvalue. An lvalue refers to an expression that can appear on the left-hand side of an assignment operator, whereas an rvalue can only appear on the right-hand side.

Tips to Fix Assignment Errors

Here are some tips to help you fix the "error: lvalue required as left operand of assignment" error:

1. Check for Typographical Errors

The error may occur due to typographical errors in your code. Make sure that you have spelled the variable name correctly and used the correct syntax for the assignment operator.

2. Check the Scope of Your Variables

The error may occur if you try to assign a value to a variable that is out of scope. Make sure that the variable is declared and initialized before you try to assign a value to it.

3. Check the Type of Your Variables

The error may occur if you try to assign a value of a different data type to a variable. Make sure that the data type of the value matches the data type of the variable.

4. Check the Memory Allocation of Your Variables

The error may occur if you try to assign a value to a variable that has not been allocated memory. Make sure that you have allocated memory for the variable before you try to assign a value to it.

5. Use Pointers

If the variable causing the error is a pointer, you may need to use a dereference operator to assign a value to it. Make sure that you use the correct syntax for the dereference operator.

Q1. What does "lvalue required as left operand of assignment" mean?

This error occurs when you try to assign a value to a non-modifiable lvalue.

Q2. How do I fix the "lvalue required as left operand of assignment" error?

You can fix this error by checking for typographical errors, checking the scope of your variables, checking the type of your variables, checking the memory allocation of your variables, and using pointers.

Q3. Why does the "lvalue required as left operand of assignment" error occur?

This error occurs when you try to assign a value to a non-modifiable lvalue, or if you try to assign a value of a different data type to a variable.

Q4. Can I use the dereference operator to fix the "lvalue required as left operand of assignment" error?

Yes, if the variable causing the error is a pointer, you may need to use a dereference operator to assign a value to it.

Q5. How can I prevent the "lvalue required as left operand of assignment" error?

You can prevent this error by declaring and initializing your variables before you try to assign a value to them, making sure that the data type of the value matches the data type of the variable, and allocating memory for the variable before you try to assign a value to it.

error: lvalue required as left operand of assignment

+(Point2D param) { Point2D temp; temp.getX() = getX() + param.getX(); temp.getY() = getY() + param.getY(); (temp); }

+(Point2D param) { Point2D temp; temp.x = getX() + param.getX(); temp.y = getY() + param.getY(); (temp); }

Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers
Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand
OverflowAI GenAI features for Teams
OverflowAPI Train & fine-tune LLMs
Labs The future of collective knowledge sharing
About the company Visit the blog

Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Get early access and see previews of new features.

Error about this lvalue required as left operand of assignment

This is my problem!!

which line is it on? – Winestone Commented Oct 12, 2014 at 9:28
3 btw, what type does stud[i].getEdad() return? what is its function declaration? – Winestone Commented Oct 12, 2014 at 9:29
Post the full code if it isn't too long – Spikatrix Commented Oct 12, 2014 at 9:33
#include <iostream> #include <ctime> #include <cstdlib> using namespace std; #define MAX 50 class moduleSupport{ private: int edad; int status; public: int getStatus(){ return status; } int getEdad(){ return edad; } void setStatus(int a){ status = a; } void setEdad(int a){ edad = a; } }; – Edzel Abliter Commented Oct 12, 2014 at 9:33
1 getEdad() returns an int by value. That is, the return is an rvalue, and you can't assign a value to it. You need to return an lvalue reference. Search for "return by reference C++". – juanchopanza Commented Oct 12, 2014 at 9:36

Source of problem I believe is

An lvalue (locator value) represents an object that occupies some identifiable location in memory (i.e. has an address). rvalues are defined by exclusion, by saying that every expression is either an lvalue or an rvalue. Therefore, from the above definition of lvalue, an rvalue is an expression that does not represent an object occupying some identifiable location in memory

With that said, an assignment expects an lvalue as its left operand i.e.

Your Answer

Reminder: Answers generated by artificial intelligence tools are not allowed on Stack Overflow. Learn more

Sign up or log in

Post as a guest.

Required, but never shown

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .

Not the answer you're looking for? Browse other questions tagged c++ or ask your own question .

Featured on Meta
Upcoming sign-up experiments related to tags
Should we burninate the [lib] tag?
Policy: Generative AI (e.g., ChatGPT) is banned
What makes a homepage useful for logged-in users

Hot Network Questions

Do countries at war always treat each other's diplomats as personae non gratae?
Etiquette for getting slides/notes from professor who missed a presentation
Clip data in GeoPandas to keep everything not in polygons
What stops a plane from rolling when the ailerons are returned to their neutral position?
How to model an optimization problem with mutual exclusivity of two variables, without introducing integer variables?
Algorithm to evaluate "connectedness" of a binary matrix
QGIS Labeling expression to format a values list in a series of 2 columns of 2 records
Why did Geordi have his visor replaced with ocular implants between Generations and First Contact?
Do IDE data lines need pull-up resistors?
How to produce this table: Probability datatable with multirow
A 90s (maybe) made-for-TV movie (maybe) about a group of trainees on a spaceship. There is some kind of emergency and all experienced officers die
Why depreciation is considered a cost to own a car?
What is the relationship between gravitation, centripetal and centrifugal force on the Earth?
How do guitarists remember what note each string represents when fretting?
Why do we care if the likelihood function is tractable?
Tubeless tape width?
what is the difference between prayer (προσευχῇ) and prayer also translated as supplication (δέησις) in Philippians 4:6?
How to Draw Gabriel's Horn
An alternative way to solve a classic problem of combinatorics
A chess engine in Java: generating white pawn moves
Could a transparent frequency-altering material be possible?
Refining material assignment in Blender geometry nodes based on neighboring faces
What does ‘a grade-hog’ mean?
Sets of algebraic integers whose differences are units

In function 'void loop()': problem with two projects

Hi guys, I keep getting the same errors in two different projects

they all seem to be related to this one:

In function 'void loop()':

Here are the codes, and bellow the list of errors. Im very very beginner and don't have a clue on where's the error. Tks

3rd project Rduino Starter Kit

const int sensorPin = A0;

const float baselineTemp = 20.0;

void setup() { Serial.begin(9600);

for(int pinNumber = 2; pinNumber<5; pinNumber++ ){ pinMode(pinNumber, OUTPUT); digitalWrite(pinNumber, LOW);

} void loop() { int sensorVal = analogRead(sensorPin); Serial.print("Sensor Value: "); Serial.print(SensorVal);

float voltage = (sensorVal/1024.0) * 5;

Serial.print(", Volts: "); Serial.print(voltage);

Serial.print (", degrees C:");

float temperature = (voltage - .5) = 100; Serial.println(temperature);

if(temperature < baselineTemp){ digitalWrite(2, HIGH); digitalWrite(3, LOW); digitalWrite(4, LOW);

} else if(temperature >= baselineTemp+2 && temperature < baselineTemp+4){ digitalWrite(2, HIGH); digitalWrite(3, HIGH); digitalWrite(4, LOW);

} else if (temperature >=baselineTemp+6){ digitalWrite(2, HIGH); digitalWrite(3, HIGH); digitalWrite(4, HIGH);

Love_Meter.ino: In function 'void loop()': Love_Meter.ino:20:14: error: 'SensorVal' was not declared in this scope Love_Meter.ino:29:36: error: lvalue required as left operand of assignment Error compiling.

Project 4 Color Mixing Lamp

const int greenLEDPin = 9; const int redLEDPin = 11; const int blueLEDPin = 10;

const int redSensor = A0; const int greensensorPin = A1; const int clueSensorPin = A2;

int redValue = 0; int greenValue = 0; int blueValue = 0;

int redSensorValue = 0; int greenSensorValue = 0; int bluesensorValue = 0;

pinMode(greenLEDPin, OUTPUT); pinMode(redLEDPin, OUTPUT); pinMode(blueLEDPin, OUTPUT);

void loop(){ redsensorValue = analogRead(redSensorPin); delay(5); greenSensorValue = analogRead(greenSensorPin); delay(5) blueSensorValue = analogRead(blueSensorPin);

Serial.print("Raw Sensor Values \t Red: "); Serial.print(redSensorValue); Serial.print("|t Green: "); Serial.print(greenSensorValue): Serial.print("| Blue "); Serial.println(blueSensorValue);

redValue = redSensorValue/4; greenValue = greenSensorValue/4; blueValue = blueSensorValue/4;

Serial.print("Mapped Sensor Values |t Red: "); Serial.print(redValue); Serial.print("\t Green: "); Serial.print(greenValue); Serial.print("\t Blue: "); Serial.println(blueValue):

analogWrite(redLEDPin, redValue); analogWrite(greenLEDPin, greenValue); analogWrite(blueLEDPin, blueValue); }

ColorMixing_sketch_feb17a.ino: In function 'void loop()': ColorMixing_sketch_feb17a.ino:29:3: error: 'redsensorValue' was not declared in this scope ColorMixing_sketch_feb17a.ino:29:31: error: 'redSensorPin' was not declared in this scope ColorMixing_sketch_feb17a.ino:31:33: error: 'greenSensorPin' was not declared in this scope ColorMixing_sketch_feb17a.ino:33:3: error: expected ';' before 'blueSensorValue' ColorMixing_sketch_feb17a.ino:38:33: error: expected ';' before ':' token ColorMixing_sketch_feb17a.ino:40:18: error: 'blueSensorValue' was not declared in this scope ColorMixing_sketch_feb17a.ino:51:28: error: expected ';' before ':' token Error compiling.

Capitalization is quite important.

SensorVal is NOT the same as sensorVal.

I don't know what you meant with

but I don't think that you intended to have two equal signs. You cannot set (voltage - .5) to the value 100.

Please notice that each error message contains the number of the line that it thinks the error is on, and the character position that it thinks is wrong. Of course, these are the line numbers AFTER the Arduino IDE has preprocessed the file.

Yeah, the right way was SensorValue but still, the same error persists...

Take a good look atbevery occurrence of the variables mentioned in the errors. There are two more that are related to capitalization or spelling not matching. You gotta at least try.

It's probably this:

(look closely)

vaj4088: SensorVal is NOT the same as sensorVal.

pk__: Yeah, the right way was SensorValue......

There are plenty of similar mistakes. Go over your code carefully and fix them. As everyone else has mentioned, take careful note of your capitalisation.

Thanks guys!!!

The problem with sensorVal was resolved!!! The right way was "s"!

Altough I keep getting this strange void error and invalue:

Love_Meter.ino: In function 'void loop()': Love_Meter.ino:28:36: error: lvalue required as left operand of assignment

I've gone line by line... Can't figure it out! I just wrote another code and the problem persists only with this in function 'void loop()':

You mean this line?

Well, what's it supposed to do?

(did you see how I used code tags too?)

pk__: Love_Meter.ino: In function 'void loop()': Love_Meter.ino:28:36: error: lvalue required as left operand of assignment I've gone line by line...

You don't have to search line by line. The error message tells you what line to look at, in this case line 28 it says. The IDE even highlights it for you.

Topic		Replies	Views
Programming Questions	4	815	May 5, 2021
Programming Questions	14	4122	May 5, 2021
Programming Questions	9	3085	May 5, 2021
Programming Questions	12	931	May 5, 2021
The Arduino Starter Kit	2	1396	May 6, 2021