What is pass by value in C language?

CServer Side ProgrammingProgramming

Pass by value is termed as the values which are sent as arguments in C programming language.

Algorithm

An algorithm is given below to explain the working of pass by value in C language.

START
Step 1: Declare a function that to be called.
Step 2: Declare variables.
Step 3: Enter two variables a,b at runtime.
Step 4: calling function jump to step 6.
Step 5: Print the result values a,b.
Step 6: Called function swap.
   i. Declare temp variable
   ii. Temp=a
   iii. a=b
   iv. b=temp
STOP

Example

Given below is the C program to swap the two numbers by using pass by value −

 Live Demo

#include<stdio.h>
void main(){
   void swap(int,int);
   int a,b;
   printf("enter 2 numbers");
   scanf("%d%d",&a,&b);
   printf("Before swapping a=%d b=%d",a,b);
   swap(a,b);
   printf("after swapping a=%d, b=%d",a,b);
}
void swap(int a,int b){
   int t; // all these statements is equivalent to
   t=a; // a = (a+b) – (b =a);
   a=b; // or
   b=t; // a = a + b;
} // b = a – b;
//a = a – b;

Output

When the above program is executed, it produces the following result −

enter 2 numbers 10 20
Before swapping a=10 b=20
After swapping a=10 b=20

Let’s take another example to know more about pass by value.

Example

Following is the C program to increment value by 5 for every call by using call by value or pass by value −

 Live Demo

#include <stdio.h>
int inc(int num){
   num = num+5;
   return num;
}
int main(){
   int a=10,b,c,d;
   b =inc(a); //call by value
   c=inc(b); //call by value
   d=inc(c); //call by value
   printf("a value is: %d\n", a);
   printf("b value is: %d\n", b);
   printf("c value is: %d\n", c);
   printf("d value is: %d\n", d);
   return 0;
}

Output

When the above program is executed, it produces the following result −

a value is: 10
b value is: 15
c value is: 20
d value is: 25
raja
Published on 11-Mar-2021 12:44:57
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