C++中一些容易迷惑的语法点总结

#include<iostream>
#include<cstring>
using namespace std;
int main(){
        int a[2][3]={{1,2,3},{4,5,6}};
        int *p=a[0];
        int (*pp)[3]=a;
        int *ppp[2]={a[0],a[1]};
        //the step is 3*4
        cout<<"a:"<<a<<endl;
        cout<<"a+1:"<<a+1<<endl;
        //the method to visit item
        cout<<"a[0][0]"<<a[0][0]<<endl;

        //the step is 4
        cout<<"a[0]:"<<a[0]<<endl;
        cout<<"a[0]+1:"<<a[0]+1<<endl;
        //the method to visit item
        cout<<"a[0][0]:"<<a[0][0]<<endl;

        //the step is 4
        cout<<"*p=a[0] p:"<<p<<endl;
        cout<<"p+1:"<<p+1<<endl;
        //the method to visit item
        cout<<"*(p+1):"<<*(p+1)<<endl;

        //the step is 3*4
        cout<<"(*pp)[3]=a pp:"<<pp<<endl;
        cout<<"pp+1:"<<pp+1<<endl;
        //the method to visit item
        cout<<"*(*(pp+1)+1)"<<*(*(pp+1)+1)<<endl;

        //the method to visit item
        cout<<"*(ppp[i]+j) or ppp[i][j]:"<<ppp[1][2]<<" or "<<*(ppp[1]+1)<<endl;
        return 0;
}

int getMemorySize(){
cout<<"char:"<<sizeof(char)<<endl;
cout<<"bool:"<<sizeof(bool)<<endl;
cout<<"int:"<<sizeof(int)<<endl;
cout<<"short int:"<<sizeof(short int)<<endl;
cout<<"long int:"<<sizeof(long int)<<endl;
cout<<"float:"<<sizeof(float)<<endl;
cout<<"double:"<<sizeof(double)<<endl;
cout<<"int*"<<sizeof(int*)<<endl;
cout<<"double*"<<sizeof(double*)<<endl;
return 0;
}

 

 

 一、基本类型变量占用的内存问题