Question

我正在尝试准备一个字符串用作目录列表。我正在处理用户输入的标题，需要删除除字母和数字之外的所有标题，然后用_替换空格。我已经能够与preg_replace稍微接近，但没有时间了解目前正则表达式的来龙去脉。

以下是string = This is a -string- that has /characters & other stuff! Let's filter it的示例。我要拍的是： this_is_a_string_that_has_characters_other_stuff_lets_filter_it

我能够接近这个代码，但是一个角色在剩下之后被删除了。结果是双_，这是可以接受的，但不是我拍摄的。

非常感谢任何帮助。这是我的尝试：

<?php
$string = " This is a -string- that has /characters & other stuff! Let's filter it?";
$cleansedstring = trim($string);
$cleansedstring = strtolower($cleansedstring);
$cleansedstring = preg_replace('/[^ \w]+/', '', $cleansedstring);
$cleansedstring = preg_replace('[\s]', '_', $cleansedstring);
echo $cleansedstring;
?>

已更新 以下是我从这里的一些建议中得出的结论，看起来非常干净并输出我拍摄的字符串......改进建议？

$string = " This is a -string- _that has /characters & other stuff! Let's filter it?23";
$cleansedstring = trim($string);
$cleansedstring = strtolower($cleansedstring);
$cleansedstring = preg_replace('/[^ \pL \pN]/', '', $cleansedstring);
$cleansedstring = preg_replace('[\s+]', '_', $cleansedstring);
echo $cleansedstring;

Answer 1

删除不需要的字符的正则表达式不应该有+，而检查空格的正则表后面需要+。

Answer 2

这也有效：

$s = "This is a -string- that has /characters & other stuff!    Let's filter it";
echo "ORIG: [{$s}]<br />";
$s = preg_replace("/[^0-9a-zA-Z\s]/","",$s);
$s = preg_replace("/\s[\s]+/"," ",$s);
$s = preg_replace("/\s/","_",$s);
$s = strtolower($s);
echo "NEW: [{$s}]<br />";

// output is
// ORIG: [This is a -string- that has /characters & other stuff! Let's filter it]
// NEW: [this_is_a_string_that_has_characters_other_stuff_lets_filter_it]

Answer 3

这是我的一个旧功能 - 略微修改为使用下划线：

public function make_url_friendly($string)
{
    $string = trim($string);

    // weird chars to nothing
    $string = preg_replace('/(\W\B)/', '',  $string);

    // whitespaces to underscore
    $string = preg_replace('/[\W]+/',  '_', $string);

    // dash to underscore
    $string = str_replace('-', '_', $string);

    // make it all lowercase
    $string = strtolower($string);

    return $string; 
}

这应该做你需要的事情

Answer 4

试试这个：

<?php
$string = " This is a -string- that has /characters & & other stuff! Let's filter it?";
$cleanstring = strtolower(trim(preg_replace('#\W+#', '_', $string), '_'));

删除所有字母和数字，替换空格。 PHP正则表达式

4 个答案: