使用PHP替换字符串中的文本 [英] Replace text in a string using PHP

问题描述

我有这个字符串:

$my_string = "http://apinmo.com/1/2/3.jpg 4444/8888/7777  http://apinmo.com/4/5/8-1.jpg";

我需要删除网址的最后两个斜杠以获取此信息，其余所有保持相同:

And I need to remove the last two slashs of the urls to get this, all the rest remain the same:

$my_NEW_string = "http://apinmo.com/123.jpg 4444/8888/7777   http://apinmo.com/458-1.jpg";

我尝试过:

$my_NEW_string = preg_replace('/(?<=\d)\/(?=\d)/', '', $my_string);

但是我明白了:

$my_NEW_string = "http://apinmo.com/123.jpg 444488887777   http://apinmo.com/458-1.jpg";

在4444/8888/7777中的斜杠已删除，这不是我所需要的.他们必须留在那里.

The slashes in 4444/8888/7777 where removed and this not what I need. They must to remain there.

更新:由于使用此代码的上下文，我需要这种方法:在"http"和"jpg"之间进行替换

UPDATE: due to the context where this code is used I need this approach: make replacements between 'http' and 'jpg'

推荐答案

这里是执行此操作并保留您的空间的另一种方法:

Here is yet another way to do this and preserve your spaces:

$my_string = "http://apinmo.com/1/2/3.jpg 4444/8888/7777  http://apinmo.com/4/5/8-1.jpg";
$string_array = explode(' ', $my_string);
print_r($string_array); // for testing

$new_array = '';
foreach($string_array AS $original) {
    $pos = strpos($original, 'http');
    if(0 === $pos){
        $new = preg_replace('/(?<=\d)\/(?=\d)/', '', $original);
        $new_array[] = $new;
    } else {
        $new_array[] = $original;
    }
}
$new_string = implode(' ', $new_array);
echo $new_string;

返回(注意保留的空格):

Returns (note the preserved spaces):

http://apinmo.com/123.jpg 4444/8888/7777  http://apinmo.com/458-1.jpg

---

编辑-纯正则表达式方法:

---

EDIT - Pure regex method:

$new_string = preg_replace('/(?<=\/\d)(\/)/', '', $my_string);
echo $new_string;

返回:http://apinmo.com/123.jpg 4444/8888/7777 http://apinmo.com/458-1.jpg

注意事项: 一种. )即使字符串中没有 空格也能正常工作 2.)如果/之间的任何数字的长度超过一位数字，则该功能不起作用. iii. )，如果第二组数字像4444/5/8888一样，第二个斜杠也将在此处删除.

CAVEATS: a. ) works even if there are no spaces in the string 2. ) does not work if any number between / is more than one digit in length. iii. ) if the second group of digits is like 4444/5/8888 the second slash would get removed here too.

正则表达式的分解方式如下:

Here is how the regex breaks down:

使用正向后匹配以匹配/后跟数字(?<=\/\d)我可以断言我要寻找的内容-我只想删除正斜杠 后的正斜杠一个数字.因此，我可以在回溯之后立即使用(\/)捕获其他正斜杠.无需包含http://即可启动，也无需包含.jpg即可退出.

Using a positive lookbehind to match a / followed by a digit (?<=\/\d) I can assert what I am looking for - I only want to remove the forward slashes after a forward slash followed by a digit. Therefore I can capture the other forward slashes with (\/) immediately after the lookbehind. There is no need to include http:// to start or .jpg to close out.

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