无法将整数转换为Char数组中的Char

Question

嘿伙计们,我正在尝试练习C++,而在这样做时我遇到了代码中的问题.我动态创建一个字符数组,然后对于每个数组索引,我想用一个整数填充该元素.我尝试将整数转换为字符,但这似乎不起作用.打印出数组元素后,什么都没有出来.我很感激任何帮助,我对此很新,谢谢.

char *createBoard()
{   
    char *theGameBoard = new char[8];    
    for (int i = 0; i < 8; i++)    
        theGameBoard[i] = (char)i;    //doesn't work

    return theGameBoard;    
}    

以下是我最终如何做到这一点.

char *createBoard()    
{    
    char *theGameBoard = new char[8];    
    theGameBoard[0] = '0';    
    theGameBoard[1] = '1';    
    theGameBoard[2] = '2';    
    theGameBoard[3] = '3';    
    theGameBoard[4] = '4';    
    theGameBoard[5] = '5';    
    theGameBoard[6] = '6';    
    theGameBoard[7] = '7';    
    theGameBoard[8] = '8';    

    return theGameBoard;    
}    

Answer 1

基本上,你的两段代码并不完全相同.

当您设置GameBoard [0] ='0'时,您实际上将其设置为值48(字符'0'的ASCII代码).因此,如果i = 0,设置GameBoard [0] =(char)i并不完全相同.您需要在ASCII表(即48)中添加'0'的偏移量,以便theGameBoard [0]实际上是0 +字符'0'的偏移量.

这是你如何做到的:

 char *createBoard()
 {
      char *theGameBoard = new char[8];
      for (int i = 0; i < 8; i++)
           theGameBoard[i] = '0' + (char)i; //you want to set each array cell
                                            // to an ASCII numnber (so use '0' as an offset)

      return theGameBoard;    
 } 

另外,像@Daniel所说的那样:确保在完成使用返回的变量后,释放你在此函数中分配的内存.像这样:

int main()
{ 
    char* gameBoard = createBoard();

    // you can now use the gameBoard variable here
    //     ...

    // when you are done with it
    // make sure to call delete on it
    delete[] gameBoard;

    // exit the program here..
    return 0;
}