Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
350 views
in Technique[技术] by (71.8m points)

c - Simple swap function...why doesn't this one swap?

I'm new to C and still trying to grasp the concept of pointers. I know how to write a swap function that works...I'm more concerned as to why this particular one doesn't.

void swap(int* a, int* b)
{
 int* temp = a;
 a = b;
 b = temp;
}

int main()
{
 int x = 5, y = 10;
 int *a = &x, *b = &y;
 swap(a, b);
 printf(“%d %d
”), *a, *b);
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You're missing *s in the swap function. Try:

void swap(int* a, int* b)
{
 int temp = *a;
 *a = *b;
 *b = temp;
}

That way, instead of just swapping the pointers, you're swapping the ints that the pointers are pointing to.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...