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$out = ""然后再$out .= 与直接 $out=啥的 有什么区别 上面有例子

WBOY
WBOYOriginal
2016-06-13 13:24:35947browse

$out = ""然后再$out .= 与直接 $out=啥的 有什么区别 下面有例子

PHP code
<!--

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-->$fp = @fsockopen($whoisserver, $port, $errno, $errstr, $timeout) or die("Socket Error " . $errno . " - " . $errstr);
    fputs($fp, $domain . "\r\n");
    $out = "";
    while (!feof($fp)){$out .= fgets($fp);}
    fclose($fp);


问下 这里的 
PHP code
<!--

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-->$out = "";
    while (!feof($fp)){$out .= fgets($fp);}

于与
PHP code
<!--

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-->
    while (!feof($fp)){$out= fgets($fp);}


有没区别 区别在哪

------解决方案--------------------
初始化操作,如果不初始化的话 $out的类型是null,与你想要的string不同 ,你可以var_dump看一下

如果用$out来做条件判断的话,不初始化的话,可能会得到不可预料的结果
------解决方案--------------------
$out = "";
while (!feof($fp)){$out .= fgets($fp);}
可以取到$fp文件所有的内容

$out = "";
while (!feof($fp)){$out = fgets($fp);}
取到的是$fp文件最后一行内容
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