c ++ delete [] 2d数组导致堆腐败

Question

当我尝试在C ++中删除二维数组时，它在Visual Studio 2017中导致错误：

HEAP CORRUPTION DETECTED: after Normal block (#530965) at 0x0ACDF348.
CRT detected that the application wrote to memory after end of heap buffer.

代码如下：

const int width = 5;
const int height = 5;

bool** map = new bool*[height];
for (int i = height; i >= 0; --i) {
    map[i] = new bool[width];
}

for (int i = height; i >= 0; --i) {
    delete[] map[i];
}
delete[] map; // error occurs here

请问代码有什么问题？

Answer 1

你离开了数组的界限;这导致了UB。请注意，范围是[0, height)，元素编号为0，…，height - 1。

从中更改两个for循环

for (int i = height; i >= 0; --i) {

至

for (int i = height - 1; i >= 0; --i) {

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PS：在大多数情况下，我们不需要手动使用原始指针和new / delete表达式，您可以使用数组（不使用原始指针），或std::vector和std::array，或智能指针。