#include<stdlib.h>

#include<stdio.h>

#include<assert.h>

int count(const char * str){//计算数组长度

        if(NULL == str) return -;

        int len=;

        char const *pt= str;

        while(*pt++)

                len++;

        return len;

}

int count1(const char* str){//计算数组长度

        assert(str!=NULL);

        const char* pt=str;

        while(*pt) pt++;

        return pt-str;

}

int main(){

        char* input1 = NULL;

        char* input2 = "";

        const char* input3 = "";

        char* input4 = "";

        char test[]={,,,,,,,,'\0'};

        int length=count(input1);

        printf("%s = %d \n",input1, count(input1));

        printf("%s = %d \n",input2, count1(input2));

        printf("%s = %d \n",input3, count1(input3));

        printf("%s = %d \n",input4, count(input4));

        printf("%s = %d \n",test, count(test));

        return ;

}