求段php 替换输出的代码

Question

循环那部分一直写不对要求如下读取a.txt内容是111,2222333,4444555,7777这样的格式如果$goods_id的值等于其中一行前面的值那么转换成后面的输出，比如$goods_id=111,那么进行替换后输出$goods_id=2222

Answer 1

$goods_id=111;
$handle=fopen("f:/test.txt","r");
while(!feof($handle)){
$line=fgets($handle,4096);
//echo$line."
";
$str=explode(",",$line);
if($str[0]==$goods_id){
echo$str[1];
}
}
fclose($handle);
                            

Answer 2

`
functiongetGoodsIpMap()
{
$fh=fopen('a.txt','r');
$goodsMap=array();
while($line=fgets($fh)!==false)
{
if(empty($line))
{
continue;
}
list($oldId,$newId)=explode(',',trim($line));
$goodsMap[$oldId]=$newId;
}
fclose($fh);
}
$goodsIdMap=getGoodsIpMap();
$newId=isset($goodsIdMap[$goodsId])?$goodsIdMap[$goodsId]:$goodsId;
`