程序代码：

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


int main()
{
    char   *str1 ="abcdefg";
    char  str2[] ="abcdefg";
    char  str3[7]={'a','b','c','d','e','f','g'};
    int len1=sizeof str1/sizeof(char);
    int len2=sizeof str2/sizeof(char);
    int len3=sizeof str3/sizeof(char);
    printf("str1 of len=%d str2 of len2=%d str3 of len3=%d\n",len1,len2,len3);
    int _len1 =(int)strlen(str1);
    int _len2 =(int)strlen(str2);
    int _len3 =(int)strlen(str3);
    printf("str1 of len=%d str2 of len2=%d str3 of len3=%d\n",_len1,_len2,_len3);
    return 0;
}



/*
样例输出:
    str1 of len=4 str2 of len2=8 str3 of len3=7
    str1 of len=7 str2 of len2=7 str3 of len3=15

*/