4、字符串操作

一、字符串初始化

//注意字符串需要有结束的标志 '\0'，不加\0会出现乱码，因为编译器会不断向后寻找直到 \0 为止
char str1[] = { 'h', 'e', 'l', 'l', 'o', '\0' };
printf("%s\n", str1);

字符数组部分初始化，剩余填0
char str2[100] = { 'h', 'e', 'l', 'l', 'o' };
printf("%s\n", str2);

如果以字符串初始化，那么编译器默认会在字符串尾部添加'\0'
char str3[] = "hello";
printf("%s\n", str3);
printf("sizeof str:%d\n", sizeof(str3)); //统计 \0
printf("strlen str:%d\n", strlen(str3)); //不统计 \0

char str4[100] = "hello";
printf("sizeof str:%d\n", sizeof(str4)); // 100
printf("strlen str:%d\n", strlen(str4)); // 5

char str5[] = "hello\0world";
printf("%s\n", str5);
printf("sizeof str5:%d\n", sizeof(str5)); //12
printf("strlen str5:%d\n", strlen(str5)); //5

char str6[] = "hello\012world"