C String Length: strlen() Function Guide

In C language, you can use the strlen() function to obtain the length of a string. This function is defined in the header file, takes a pointer to the string as a parameter, and returns the length of the string (excluding the null terminator character). Below is an example code:

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

int main() {
    char str[100];
    printf("输入一个字符串：");
    fgets(str, 100, stdin); // 从标准输入读取字符串
    str[strcspn(str, "\n")] = 0; // 去除fgets()函数读取的换行符

    int len = strlen(str);
    printf("字符串的长度为：%d\n", len);

    return 0;
}

In the example above, we used the fgets() function to read a string from standard input, removed the newline character with the strcspn() function. We then used the strlen() function to get the length of the string and print the result.