C语言多种获取字符串长度的方法

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int i=10;

sizeof(i);//表达式

char str[]="hello world";

sizeof(str);

sizeof(double);//数据类型

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size_t strlen(const char *str);

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int get_length(char str[])

{

    char *p = str;

    int count = 0;

    while (*p++ != '\0')

    {

        count++;

    }

    return count;

}

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#include <stdio.h>

#include <string.h>

int get_length(char str[])

{

    char *p = str;

    int count = 0;

    while (*p++ != '\0')

    {

        count++;

    <360>}

    return count;

}

int main()

{

    char str[] = "abcd";

    int count1 = sizeof(str);

    int count2 = strlen(str);

    int count3 = get_length(str);

    printf("use sizeof the length is %d\n", count1);

    printf("use strlen the length is %d\n", count2);

    printf("use get_length the length is %d\n", count3);

    return 0;

}