Question

您好我正试图让我的for循环动态计数向后或向前。（处理积极到消极和消极到积极）

以下是我的代码，但它似乎无法正常运行。（我不明白如何使用变量将for循环从+1更改为-1）

function _allbetween($coords1, $coords2) {
$blocks = "";

if ($coords2[0] == 0 || $coords2[1] == 0 || $coords2[2] == 0) {
    $temp2 = $coords2[0].",".$coords2[1].",".$coords2[2];
    $temp1 = $coords1[0].",".$coords1[1].",".$coords1[2];
    $coords1 = explode(",", $temp2);
    $coords2 = explode(",", $temp1);
}

for ($i=0; $i<=2; $i++)
{
  if (substr($coords2[$i],0,1) == "-") { //if the value is negative
   $step[$i] = "--"; //substract the for loop
  } else { //else
   $step[$i] = "++"; //add the for loop
  }
}

for ($i1=$coords1[0]; $i1<=$coords2[0]; $i1.$step[0])
  {
        for ($i2=$coords1[1]; $i2<=$coords2[1]; $i2.$step[1])
            {
                for ($i3=$coords1[2]; $i3<=$coords2[2]; $i3.$step[2])
                    {
                        $blocks.= $i1.",".$i2.",".$i3."|";
                    }
            }
  }
return $blocks;
}

任何人都能看到我做错了什么？

Answer 1

没关系！

我现在看到php自动处理正值和负值而不将++更改为 -

Answer 2

也许你正在寻找这个。

for ($i=0; $i<=2; ) // Note the removed $i++ here
{
  if (substr($coords2[$i],0,1) == "-") { //if the value is negative
   $i--; //$step[$i] = "--"; //substract the for loop
  } else { //else
   $i++; //$step[$i] = "++"; //add the for loop
  }
}

动态For循环（向前或向后计数）

2 个答案: