从 PHP 中特定字符串的开头删除字符串

Question

我在 php 中有一个这样的 url 字符串：$string = 'test.xyz/builder-list/?price=301-500%2C501-1000&builder_country=6442%2C6780%2C6441';我想从price以 `%2c 开头的 URL 字符串中的查询值中删除特定字符串。例如：test.xyz/builder-list/?price=301-500%2C501-1000&builder_country=6442%2C6780%2C6441intotest.xyz/builder-list/?price=301-500&builder_country=6442%2C6780%2C6441test.xyz/builder-list/?price=-200%2C400-500&builder_region=1223%2C3445intotest.xyz/builder-list/?price=-200&builder_region=12%2C33test.xyz/builder-list/?builder_state=45%2C76&price=-200%2C400-500intotest.xyz/builder-list/?builder_state=45%2C76&price=-200我尝试使用这个preg_replace函数，但它删除了所有的%2C字符串preg_replace('/' . preg_quote('%2C') . '.*?/', '', $string);

Answer 1

如果您使用的是正则表达式，则必须price专门捕获并将分隔符的前后部分捕获%2C到单独的正则表达式组中并替换它们。它看起来像下面这样：

preg_replace('/(price\=)([^&]*)%2C[^&]*/', '$1$2', $str)'

               -------- -------             ----

                Grp 1.   Grp 2.              Only grp 1 and 2.

片段：

<?php

$tests = [

        'test.xyz/builder-list/?price=301-500%2C501-1000&builder_country=6442%2C6780%2C6441',

        'test.xyz/builder-list/?price=-200%2C400-500&builder_region=1223%2C3445',

        'test.xyz/builder-list/?builder_state=45%2C76&price=-200%2C400-500',

        'test.xyz/builder-list/?builder_state=45%2C76&price=%2C400-500'

    ];

foreach($tests as $test){

    echo preg_replace('/(price\=)([^&]*)%2C[^&]*/', '$1$2', $test),PHP_EOL;

}

演示： http://sandbox.onlinephpfunctions.com/code/f5fd3acba848bc4f2638ea89a44c493951822b80

Answer 2

$string = 'test.xyz/builder-list/?builder_state=45%2C76&price=-200%2C400-500';

//Separate string based on & an make an array $q

$q = explode('&', $string); 

//Go through each item in array $q and make adjustments

//if it's the price-query

foreach($q as &$item) {

    if (stristr($item,'price') !== false) {

        //Just leave left the first part of

        //this item before %2C

        $pos = strpos($item, '%2C');

        $item = substr($item,0,$pos); 

        break; //No need being here in this loop anymore

    }

}

//Implode back to original state and glue it together with ampersand

$result = implode('&', $q);

$result将包含：

test.xyz/builder-list/?builder_state=45%2C76&price=-200

Answer 3

正则表达式的另一种选择是通过parse_str.

使用第一个strtok获取基本 url 并将其分开，以便您可以在parse_str.

在将其分离并加载到 中之后parse_str，您可以对查询字符串的各个部分进行更改。如果您想更改价格，请像这样操纵它。

使用另一个只是为了有效地修剪or ( )strtok之后的字符并重新分配。,%2C

http_build_query最后，使用之前操作中分离的基本 url 连接的方式重新附加查询字符串。

$string = 'test.xyz/builder-list/?price=-200%2C400-500&builder_region=1223%2C3445';

$base_url = strtok($string, '?');

parse_str(str_replace("{$base_url}?", '', $string), $data);

$data['price'] = strtok($data['price'], ',');

$final_string =  "{$base_url}?" . http_build_query($data);

echo $final_string;