#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, const char *argv[])
{
char *p = "120";
printf("%ld\n", atol(p)); // atol: 转换成长整型
p = "12.3";
printf("%.2f\n", atof(p)); // atof: 转换成浮点数
return 0;
}