How do you trim white space on beginning and the end of each new line with PHP or regex

问题

How do you trim white space on beginning and the end of each new line with PHP or regex?

For instance,

$text = "similique sunt in culpa qui officia 

     deserunt mollitia animi, id est 

  laborum et dolorum fuga   

";

Should be,

$text = "similique sunt in culpa qui officia

deserunt mollitia animi, id est

laborum et dolorum fuga
";

回答1:

Using a regex is certainly quicker for this task. But if you like nesting functions this would also trim whitespace from all lines:

$text = join("\n", array_map("trim", explode("\n", $text)));

回答2:

<textarea style="width:600px;height:400px;">
<?php

$text = "similique sunt in culpa qui officia 

     deserunt mollitia animi, id est 

  laborum et dolorum fuga   

";

echo preg_replace("/(^\s+|\s+$)/m","\r\n",$text);

?>
</textarea>

I added the testarea so you can see the newlines clearly

回答3:

1st solution :

Split your original string with the newline character with explode, use trim on each token, then rebuild the original string ...

2nd solution :

Do a replace with this regular expression \s*\n\s* by \n with preg_replace.

回答4:

You can use any horizontal whitespace character switch and preg_replace function to replace them with nothing:

$text = trim(preg_replace('/(^\h+|\h+$)/mu', '', $text));

If you need preserve whitespace on file ned remove trim or replace with ltrim function

回答5:

Here another regex that trims whitespace on beginning an end of each line..

$text = preg_replace('/^[\t ]+|[\t ]+$/m', '', $text);

See /m modifier

回答6:

Mario's solution works well (thank you for that mario - saved my day). Maybe somebody can explain though why it turned my later checks for cross-platform compatible line breaks such as

    (strstr($text, PHP_EOL))

to FALSE even when the line breaks existed.

Anyway, changing "\n" to PHP_EOL fixed the issue:

    $text = join(PHP_EOL, array_map("trim", explode(PHP_EOL, $text)));

来源：https://stackoverflow.com/questions/7335060/how-do-you-trim-white-space-on-beginning-and-the-end-of-each-new-line-with-php-o

标签

php

regex

whitespace

trim