我的代码给了我期望的无符号字符指针的不同长度。 我以为我应该得到12(或13)或0(或1)为pph和pphChar。 我的问题是什么?当我重复跑步时,每次都得到不同的长度和长度的结果。什么是无符号字符strlen的正确方法*
我怎样才能得到pph的长度?
我是否需要在末尾加上'\ n'来确定长度?
我使用VS2010,XP和C++。
#include "stdafx.h"
#include <stdlib.h>
#include <Windows.h>
#include <stdio.h>
#include <tchar.h>
typedef unsigned char uint8_t;
int _tmain(int argc, _TCHAR* argv[])
{
int length;
int len = 13;
uint8_t *phh;
char * phhChar;
printf("assigned mem %d\n", sizeof(unsigned char)*len);
phh = (unsigned char *) malloc(sizeof(unsigned char)*len);
phhChar = (char *) malloc(sizeof(char)*len);
phh[0] = (unsigned char) '1';
phh[1] = (unsigned char) '2';
phh[2] = (unsigned char) '3';
phh[3] = (unsigned char) '4';
phh[4] = (unsigned char) '5';
phh[5] = (unsigned char) '6';
phh[6] = (unsigned char) '7';
phh[7] = (unsigned char) '8';
phh[8] = (unsigned char) '9';
phh[9] = (unsigned char) '0';
phh[10] = (unsigned char) '1';
phh[11] = (unsigned char) '2';
phh[12] = (unsigned char) '\n';
phhChar[0] = (char) '\n';
printf("size of char %d\n", sizeof(unsigned char));
length = strlen((const char*)phh);
int oneLength = strlen((const char*)phhChar);
printf("len %d\n", length);
printf("onelebgth %d\n", oneLength);
OUTPUT
分配MEM 13
大小炭1
len个32 - 每次都不同
oneLength 32 - 每次都不同
您不会零终止字符串,所以结果是随机的。 – bmargulies
顺便说一下,'sizeof(char)'和'sizeof(unsigned char)'保证是1. –
你可以用C++编写C语言,但是这种方式不符合目的吗? – David