Linux下c++中的atoi、atol、atoll、atof函数调用实例
本文中调用的四个函数如下:
atoi函数:将字符串转化为int类型变量
atol函数:将字符串转化为long类型变量
atoll函数:将字符串转化为long long类型变量
atof函数:将字符串转化为double类型变量
这些函数的转化过程,都是将一个字符串的可读部分取到变量中
遇到不可读的部分,则直接终止读取
调用示例:
#include <stdio.h>
#include <stdlib.h>
#define Seperate(); printf("\n=============\n\n");
int main()
{
Seperate();
//atoi
printf("atoi: string to integer\n");
const char* s00 = "1234567890";
printf("%s -> %d\n", s00, atoi(&s00[0]));
const char* s01 = "123.4";
printf("%s -> %d\n", s01, atoi(&s01[0]));
const char* s02 = "xyz";
printf("%s -> %d\n", s02, atoi(&s02[0]));
const char* s03 = "1234xyz";
printf("%s -> %d\n", s03, atoi(&s03[0]));
Seperate();
//atol
printf("atol: string to long\n");
const char* s10 = "1234567890123";
printf("%s -> %ld\n", s10, atol(&s10[0]));
const char* s11 = "123.4";
printf("%s -> %ld\n", s11, atol(&s11[0]));
const char* s12 = "xyz";
printf("%s -> %ld\n", s12, atol(&s12[0]));
const char* s13 = "1234xyz";
printf("%s -> %ld\n", s13, atol(&s13[0]));
Seperate();
//atoll
printf("atoll: string to long long\n");
const char* s20 = "1234567890123";
printf("%s -> %lld\n", s20, atoll(&s20[0]));
const char* s21 = "123.4";
printf("%s -> %lld\n", s21, atoll(&s21[0]));
const char* s22 = "xyz";
printf("%s -> %lld\n", s22, atoll(&s22[0]));
const char* s23 = "1234xyz";
printf("%s -> %lld\n", s23, atoll(&s23[0]));
Seperate();
//atof
printf("atof: string to double\n");
const char* s30 = "1234567890";
printf("%s -> %lf\n", s30, atof(&s30[0]));
const char* s31 = "123.4";
printf("%s -> %lf\n", s31, atof(&s31[0]));
const char* s32 = "xyz";
printf("%s -> %lf\n", s32, atof(&s32[0]));
const char* s33 = "1234xyz";
printf("%s -> %lf\n", s33, atof(&s33[0]));
Seperate();
return 0;
}
运行效果:
END
作者:柒月
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