Question

我已经有一个java程序可以正常工作。我尝试在php中编写相同的文件并遇到一些错误。例如，在此代码中

for ($i=0; $i<64; $i++) {
    $r=$i/8; 
    $c=$i%8;
    $temp=1;
    for ($j=-1; $j<=1; $j+=2) {
        for ($k=-1; $k<=1; $k+=2) {
            while(" " == $chessBoard[$r+$temp*$j][$c+$temp*$k])
            {
                 //some other code here
            }
        }
    }
}

$ chessBoard是一个二维数组

$chessBoard= array
(
    array("r","k","b","q","a","b","k","r"),
    array("p","p","p","p","p","p","p","p"),
    array("0","0","0","0","0","0","0","0"),
    array("0","0","0","0","0","0","0","0"),
    array("0","0","0","0","0","0","0","0"),
    array("0","0","0","0","0","0","0","0"),
    array("P","P","P","P","P","P","P","P"),
    array("R","K","B","Q","A","B","K","R")
);

我知道当我试图访问$ chessBoard [$ r + $ temp * $ j] [$ c + $ temp * $ k]时会发生错误，例如$ r为0且$ j为-1，然后我得到0 + 1 * -1这是-1，但我不知道如何摆脱这个问题，仍然让程序正常工作。我仍然不清楚为什么我在java中没有相同的问题。

Answer 1

在代码之前

while(" " == $chessBoard[$r+$temp*$j][$c+$temp*$k])
{
    //some other code here
}

投入：

if($r+$temp*$j < 0 || $c+$temp*$k) continue;

这将转到for循环的下一次迭代，不会遇到任何indexoutofboundsexception

PHP Undefined offset：-1，如何跳过负索引？

1 个答案: