如何从PHP中的字符串中删除所有非字母数字和非空格字符？

Question

I want to remove all non-alphanumeric and space characters from a string. So I do want spaces to remain. What do I put for a space in the below function within the [ ] brackets:

ereg_replace("[^A-Za-z0-9]", "", $title);

In other words, what symbol represents space, I know \\n represents a new line, is there any such symbol for a single space.

Answer 1

Just put a plain space into your character class:

[^A-Za-z0-9 ]

For other whitespace characters (tabulator, line breaks, etc.) use \\s instead.

You should also be aware that the PHP's POSIX ERE regular expression functions are deprecated and will be removed in PHP 6 in favor of the PCRE regular expression functions . So I recommend you to use preg_replace instead:

preg_replace("/[^A-Za-z0-9 ]/", "", $title)

Answer 2

如果你只想要一个文字空间，就把它放进去。像'空白字符'那样的组，比如tab和换行符是\\ s

Answer 3

The accepted answer does not remove spaces.

Consider the following

$string = 'tD  13827$2099';
$string = preg_replace("/[^A-Za-z0-9 ]/", "", $string);

echo $string;

> tD  138272099

Now if we str_replace spaces, we get the desired output

$string = 'tD  13827$2099';
$string = preg_replace("/[^A-Za-z0-9 ]/", "", $string);

// remove the spaces
$string = str_replace(" ", "", $string);

echo $string;

> tD138272099