使用数组指针进行Cout打印-奇怪的行为

Question

我在玩指针，得到了我没有想到的结果：

#include <iostream>
#include <vector>

int main() {
    int arr[4] = { 1, 2, 3, 4 };
    int* pArr = arr;
    std::cout << "First number: " << *pArr << " at address: " << pArr;
    pArr++;
    std::cout << "\nSecond number: " << *pArr << " at address: " << pArr;
    pArr++;
    std::cout << "\nThird number: " << *pArr << " at address: " << pArr;
    pArr++;
    std::cout << "\nFourth number: " << *pArr << " at address: " << pArr;
    
    int* pArr2 = arr;
    std::cout << "\n"
        << *pArr2++ << "\n"
        << *pArr2++ << "\n"
        << *pArr2++ << "\n"
        << *pArr2++ << "\n";
    /*
    int* pArr2 = arr;
    std::cout << "\n"
        << ++ * pArr2 << "\n"
        <<  * ++pArr2 << "\n";
    */
}

两种不同的结果：

1 2 3 4-按预期使用第一种方法

Answer 1

此代码：

std::cout << "\n" << *pArr2++ << "\n";
std::cout << "\n" << *pArr2++ << "\n";

具有定义良好的parr修改顺序，并将打印

1
2

但是这个代码：

std::cout << "\n" << *pArr2++ << "\n" << *pArr2++ << "\n";

1
2