C++各种类型指针的长度（1）

曾经终败给现在 2022-12-21 09:25 148阅读 0赞

#include <windows.h>
    #include <string>
    
    using namespace std;
    
    int APIENTRY WinMain(HINSTANCE hInstance,
                         HINSTANCE hPrevInstance,
                         LPSTR     lpCmdLine,
                         int       nCmdShow)
    {
     	/* TODO: Place code here.*/
     	char szBuffer[100];
     	
     	 int a = 10;
         int *pi = &a;
         wsprintf(szBuffer, "%d",sizeof(pi));
         MessageBox(NULL,szBuffer,TEXT("int类型指针的长度"),0);
    
         double b = 10;
         double *pd = &b;
         wsprintf(szBuffer, "%d",sizeof(pd));
         MessageBox(NULL,szBuffer,TEXT("double类型指针的长度"),0);
         
         char* pc = "abc";  
         string* ps;  
         char** ppc = &pc;  
         void (*pf)();// 函数指针  
         //sizeof( pc ); // 结果为4  
         //sizeof( ps ); // 结果为4  
         //sizeof( ppc ); // 结果为4  
         //sizeof( pf );// 结果为4 
         
         wsprintf(szBuffer, "%d",sizeof( pc ));
         MessageBox(NULL,szBuffer,TEXT("char*类型指针的长度"),0);
         wsprintf(szBuffer, "%d",sizeof( ps ));
         MessageBox(NULL,szBuffer,TEXT("string*类型指针的长度"),0);
         wsprintf(szBuffer, "%d",sizeof( ppc ));
         MessageBox(NULL,szBuffer,TEXT("char** 类型指针的长度"),0);
         wsprintf(szBuffer, "%d",sizeof( pf ));
         MessageBox(NULL,szBuffer,TEXT("函数指针的长度"),0);     
    
    	return 0;
    }

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[20201115211111181.png]: /images/20221120/092a0b331e9447bf95a9d5d9718279e2.png
[2020111521112025.png]: /images/20221120/2318f6da6d844153a9d63118ad64d49f.png
[2020111521113923.png]: /images/20221120/f200a29cd17047b08366247b10c9cd6d.png
[20201115211149636.png]: /images/20221120/abceee2b9f624fcb940625023e64dfbc.png
[20201115211156884.png]: /images/20221120/7466a5750a3041bf92d8ce124db7fdec.png
[2020111521120666.png]: /images/20221120/ed712bae53644197b9a92c851d5f6292.png