linux c 取绝对值

#include <stdio.h>
#include <stdlib.h>

int main() {
    int num = -10;
    int abs_num = abs(num);
    printf("The absolute value of %d is %d
", num, abs_num);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main() {
    long num = -1000000L;
    long abs_num = labs(num);
    printf("The absolute value of %ld is %ld
", num, abs_num);
    return 0;
}

#include <stdio.h>
#include <math.h>

int main() {
    double num = -123.456;
    double abs_num = fabs(num);
    printf("The absolute value of %f is %f
", num, abs_num);
    return 0;
}