What is difference between pass by value and pass by pointer?

Answer:

In c we can pass the parameters in a function in two different ways.

(a)Pass by value: In this approach we pass copy of actual variables in function as a parameter. Hence any modification on parameters inside the function will no reflect in the actual variable.



 For example:

#include<stdio.h>

void main(){

    int a=5,b=10;

    swap(a,b);

    printf("%d      %d",a,b);

}

void swap(int a,int b){

    int temp;

    temp =a;

    a=b;

    b=temp;

}

Output: 5    10

(b)Pass by reference: In this approach we pass memory address actual variables in function as a parameter. Hence any modification on parameters inside the function will reflect in the actual variable. For example:

#include<stdio.h>

void main(){

    int a=5,b=10;

    swap(&a,&b);

    printf("%d      %d",a,b);

}

void swap(int *a,int *b){

    int  *temp;

    *temp =*a;

    *a=*b;

    *b=*temp;

}

Output: 10 5