c++ - 重新增长数组时出错：写入时缓冲区溢出

Question

所以我试图重新增长这个一维动态数组，但我无法修复这个错误： 写入“new_arr”时缓冲区溢出：可写大小是“newLength*1”字节，但可能会写入 2 个字节

void regrow(char *&arr, int &length,int newLength) //Funcion to regrow an array
{
    char* new_arr = new char[newLength];
    for (int index = 0; index < length; index++)
    {
        new_arr[index] = arr[index];   //**Error occurs here** 
    }
    length = newLength;
    delete[] arr;
    arr = new_arr;
}

标签： c++arraysmemorydynamicmemory-leaks

Answer 1

缓冲区溢出错误通常会检测您是否尝试写入未分配的空间，这可能是由于newLength小于length自身的空间，可以通过 if-return 检查避免：

#include <iostream>

void regrow(char *&arr, int &length,int newLength) //Funcion to regrow an array
{
    if(length >= newLength){ //Check for correct input
        return;
    }else{

    char* new_arr = new char[newLength];
    for (int index = 0; index < length; index++)
    {
        new_arr[index] = arr[index];   //**Error occurs here**
    }
    length = newLength;
    delete[] arr;
    arr = new_arr;
    }
}

int main()
{
    int a = 5;
    int b = 8;
    char*array = new char[a]{'C','B','a','d','f'};

    regrow(array,a,b);


    for(int i = 0; i < a; ++i){
        std::cout << array[i] << std::endl;
    }

    return 0;
}