c++ 中字符串的字符数与字节数

以你之姓@ 2023-07-13 15:27 177阅读 0赞

c++中字符数是字符的个数，字节数是在内存中所占的大小（siziof（）），每一个字符串在内存中都以'/0'结束。

#include<iostream>
    using namespace std;
    #include <atlstr.h >
    int main()
    {
    	string str_string="test13";
    	CString str_Cstring=_T("test11");
    	char str_char='t';
    	char strchar[]="qwer";
    
        //二维字符数组测试
    	char a[3][4]={"111","132","323"};
    
    	a[2][2]=a[2][1];
    	a[2][2]='1';
    	char fore[4]="111";
    	//scanf("%s",a[2]); //可赋值
    	strcpy(a[2],"111");  //字符串拷贝
    	memcpy(a[2],"222",4); //内存拷贝
    	//二维字符数组测试
    	
    	printf_s(_T("str_string字符数为：%d\n"),str_string.size());
    	printf_s(_T("str_Cstring字符数为：%d\n"),str_Cstring.GetLength());
    
    	printf_s(_T("str_string字节数为：%d\n"),sizeof(str_string));    //string是类，不是数据类型，只是处理字符串的类，可以转换为字符串char a[大小];  strcpy(a,str_string.c_str);（a字符串以'\0结尾'）
    	printf_s(_T("str_Cstring字节数为：%d\n"),sizeof(str_Cstring));   //类似于char[]数组，存放字符串都以'\0'结尾,'\0'占一个字节
    	printf_s(_T("str_char字节数为：%d\n"),sizeof(str_char));
    	printf_s(_T("strchar字节数为：%d\n"),sizeof(strchar));
    
    	printf_s(_T("本机基本变量类型所占字节数\n"));
    	printf_s(_T("char所占字节数:%d\n"),sizeof(char));
    	printf_s(_T("BYTE所占字节数:%d\n"),sizeof(BYTE));     //typedef unsigned char       BYTE;
    	printf_s(_T("int所占字节数:%d\n"),sizeof(int));
    	printf_s(_T("float所占字节数:%d\n"),sizeof(float));
    	printf_s(_T("short所占字节数:%d\n"),sizeof(short));
    	printf_s(_T("WORD所占字节数:%d\n"),sizeof(WORD));     //typedef unsigned short      WORD;
    	printf_s(_T("float所占字节数:%d\n"),sizeof(float));
    	printf_s(_T("double所占字节数:%d\n"),sizeof(double));
    	printf_s(_T("longdouble所占字节数:%d\n"),sizeof(long double));
    	printf_s(_T("long所占字节数:%d\n"),sizeof(long));   
    	printf_s(_T("long long所占字节数:%d\n"),sizeof(long long)); 
    	printf_s(_T("DWORD所占字节数:%d\n"),sizeof(DWORD));  //typedef unsigned long       DWORD;
    	printf_s(_T("bool所占字节数:%d\n"),sizeof(bool));    //标准c++ bool类型
    	printf_s(_T("BOOL所占字节数:%d\n"),sizeof(BOOL));    //typedef int                 BOOL;
    	printf_s(_T("uint所占字节数:%d\n"),sizeof(UINT));    //typedef unsigned int        UINT;
    
    
    	system("pause");
    }

测试结果如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIyNjQyMjM5_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIyNjQyMjM5_size_16_color_FFFFFF_t_70]: /images/20230529/294fc1c901ab4714ab1fc3b4a0c648bb.png