php - PHP：str_replace 仅替换第一次出现

Question

对于这段代码，有谁知道为什么只$unuseful替换字符串中的第一个单词？

$unuseful = array(" is ", " the ", " for ", " and ", " with "," that ", " this "," or ", ",",";","/","?","!",".");
$aux = str_replace($unuseful, " " , $statement);

"dude cost that free the dude the "-> dude cost free dude the

“dude cost that free the dude the the”-> dude cost free dude the the

提前致谢！

Answer 1

那是因为您放置了前导和尾随空格。

它替换了“ the ”一次，因为“ the ”只有 3 个空格，而您正在寻找替换 4 个空格。

Answer 2

    for($i=0;$i<count($unuseful);$i++)
    {$statement = str_replace($unuseful[$i], " " , $statement);}
$aux=$statement;

Answer 3

<?php
$unuseful = array('/\s+is\s+/', '/\s+the\s+/', '/\s+for\s+/', '/\s+and\s+/', '/\s+with\s+/','/\s+that\s+/', '/\s+this\s+/','/\s+or\s+/', '/,/','/;/','/\//','/\?/','/\!/','/\./');

$challenge = 'dude cost that free the dude the the';
echo preg_replace($unuseful, ' ', $challenge)."\n";
?>

给出：

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