Assignment Operator in C Language | L- value Error in C programming

Assignment-Operator-in-c-Language-and-compound-statements-in-c

Introduction:

In our previous articles, we discussed the Arithmetic Operators in C Language. In today’s article, We will learn about the Assignment Operator in C Programming. We also discuss the L-Value error in programming.

Assignment Operator in C Langauge ( = ) :

The C programming language has assignment operators to create and assign values to the variables.

We represent the Assignment operator using the equal to( = ) symbol in C programming.

Syntax Of Assignment Operator:

1	L-Value = R-Value

The assignment operator is for used assigning values. In general assignment operator assigns the value of the right-hand ( R-Value) side operand to the Left-hand (L-Value) side Operand.

The assignment operator is a binary operator so it must need two operands.

The assignment operator has two values. The Left-side value is called as L-Value and The Right-side value is called as R-Value.

The Assignment Operation will copy the R-Value to L-Value.

The left-side value ( L-Value ) of the Assignment Operator must be a Variable.

The assignment operator has the Lowest Precedence or Priority compared to all other operators except Comma Operator.

For full Priority of Operators please visit – see full priority table/precedence table

Example Program to understand Assignment Operator:

#include<stdio.h>

int main()

{

int x;

// Here we are assigning the value '10' to variable 'x'

x = 10;

// Print the value of 'x' using 'printf'

printf("value of x is : %d \n", x);

return 0;

}

In above Example x = 10 is assignment operation.

Here x is the left-side value or L-Value and The value 10 is the right-side value or R-Value, By using the assignment operator we assigned the value 10 to the variable x.

Program Output:

1	value of x is : 10

As you can see the value of x is 10.

Example 2 : L – Value Error in C programming :

#include<stdio.h>

int main()

{

// Create a Variable 'x' and assign value '10'

int x = 10;

// Here we are trying to assign the value of 'x' to '20'

// As 20 is constant, This operation is not allowed.

// Which results into the compilation error.

20 = x;

// Try to print the value of 'x'

printf("value of x is : %d n", x);

return 0;

}

The Left-side value of the Assignment Operator must be Variable. So we basically trying to assign R-Value to L-Value. So L-Value must-have capacity to store the R-Value. But constants and numbers can’t store a value.

📢 The Left-side or L-Value of the Assignment Operator must be a Variable.

Program Output

1 2	error: lvalue required as left operand of assignment 20 = x ;

Complex Assignment Operations in C Programming:

In the C programming language, We have few compound assignment operators to perform the assignments along with some other arithmetic operations.

For example,

x = 5; // simple assignment

x += 10; // compound operation

Simple Assginment Operation:

x = 10;

This is a simple assignment, Here we have created a variable x and assigned value 10 to x.

Compound Addition ( Add then Assigne += ):

x += 20;

This is a compound operation. Which is equal to

x = x + 20;

Here first x+20 is calculated then x is updated with the resulting value of x+20 operation.

Similarly, we can have other compound arithmetic operations, Please look at the following table for all compound Operations.

Operator	Syntax	Description	Example
Assignment ( = )	a = b	Creates variable a and assigns value b to it.	> a = 10; > printf("%d", a); 10
Compound Addition ( += ) or Add and Assign	a += b	First, Evaluate the addition of a+b then assign results to a Step 1: a+b Step 2 : a = a+b	> printf("%d", a); 10 > a += 10 > printf("%d", a); 20
Compound Subtract ( -= ) or Subtract and Assign	a -= b	First, Evaluate the a-b then assign the result to a	> printf("%d", a); 10 > a -= 10 > printf("%d", a); 0 (zero)
Compound Product ( *= ) or Multiply and Assign	a *= b	First, Evaluate the a*b then assign the result to a	> printf("%d", a); 10 > a *= 10 > printf("%d", a); 100
Compound Division ( /= ) or Division and Assign	a /= b	First, Evaluate the a/b then assign the result to a	> printf("%d", a); 10 > a /= 10 > printf("%d", a); 1
Compound Modulus ( %=) or Modulus and Assign	a %= b	First, Evaluate the a%b then assign the result to a	> printf("%d", a); 10 > a %= 10 > printf("%d", a); 0 ( zero )

The Compound Assignment statements are elegant and try to use them in the programs.

Conclusion:

In this article, We discussed the Assignment Operators and Compound Assignment operators in the C language. We also looked at a few example code snippets and L-Value Error.

Assignment Operator in C Language | L- value Error in C programming

Introduction: