字符串的初始化

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

/*c语言没有字符串类型，通过字符数组模拟
c语言字符串以字符'\0'结尾*/
int main() {
    //不指定长度，没有'\0'结束符. 有多少个元素就有多长
    char buf[] = {'a', 'b', 'c'};
    printf("buf = %s\n", buf); //buf = abc�]�
    //指定长度，后面没有元素，自读补0
    char buf1[100] = {'a', 'b', 'c'};
    printf("buf1 = %s\n", buf1); //buf1 = abc

    // 所有元素赋值为0
    char buf2[100] = {0};

    //字符0有对应的assic码
    char buf3[100] = {'a', 'b', 'c', '0', '6'}; 
    printf("buf3 = %s\n", buf3);//buf3 = abc06

    //数字0和\0等价，表示字符串结束
    char buf4[100] = {'a', 'b', 'c', 0, '6'}; 
    printf("buf4 = %s\n", buf4);//buf4 = abc

    char buf5[100] = {'a', 'b', 'c', '\0', '6'};
    printf("buf5 = %s\n", buf5); //buf5 = abc

    //通常直接使用字符串初始化
    char buf6[] = "hello world!!!";
    // strlen测试字符串长度，不包括\0, sizeof测试数组长度，包含\0
    printf("strlen = %d  sizeof = %d\n", strlen(buf6), sizeof(buf6)); //strlen = 14  sizeof = 15

    char buf7[100] = "hello world!!!";
    printf("strlen = %d  sizeof = %d\n", strlen(buf7), sizeof(buf7)); //strlen = 14  sizeof = 100
    return 0;
}