输入一个字符串，计算出字符串长度 ( 不能用strlen函数）

/* C Program to find the length of a String without
 *  using any standard library function
 */
#include <stdio.h>
int main()
{
    /* Here we are taking a char array of size
     * 100 which means this array can hold a string
     * of 100 chars. You can change this as per requirement
     */
    char str[100],i;
    printf("Enter a string: \n");
    scanf("%s",str);

    // '\0' represents end of String
    for(i=0; str[i]!='\0'; ++i);
       printf("\nLength of input string: %d",i);

    return 0;
}

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