if语句:求x的绝对值
#include<stdio.h>
void main()
{
int x,y;
scanf("%d", &x);
printf("x=%d\n",x);
y=x;
if(x<0);
y=-x;
printf("|%d|=%d",x,y);
}

#include<stdio.h>
void main()
{
int x,y;
scanf("%d", &x);
printf("x=%d\n",x);
y=x;
if(x<0);
y=-x;
printf("|%d|=%d",x,y);
}
