CODEWITHSUNDEEP
global-variables
Pavan Kumar
Pavan Kumar

Reputation: 77

c programming global variable updating

iam new to c programming and written a function to swap two numbers.the problem is that inside swap function variables are getting updated correctly but the global variables a and b are not changing.Please help me with any misconception I have.Thanks for the help.

int main(){

int a = 2; int b = 3;
void swap(int a , int b){
    int c= a;
    a = b;
    b = c;
}
swap(a,b);
printf("%d\n",a);
printf("%d\n",b);
    return 0;
}

Upvotes: 1

Views: 932

Answers (1)

AverageToaster
AverageToaster

Reputation: 96

In C, primitive variables are passed by value, not by reference. When the swap method is called, the a and b parameters in the swap method are not the same a and b as in the main() method. Only the values of a and b are passed into the method. So while in the swap method, a and b are swapped, but the a and b in main are not actually altered.

What you need to do is pass by reference. An example of pass by reference is here.

Upvotes: 1

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