内置函数 strlen

//内置函数   strlen
//计算字符串的实际长度，不含字符串结束标准\0

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

void main()
{

    char words1[] = {'z','h','e','n','g','l','e','i','\0'};
    char words2[] = "zhenglei";
    char words3[] = "你好，zero！";  //一个中文字符占两个字节

    printf("words1长度为：%d\n",strlen(words1));
    printf("words2长度为：%d\n",strlen(words2));
    printf("words3长度为：%d\n",strlen(words3));
}