使用 PHP 正则表达式删除独立数字

Question

How can I remove independent numbers in a string in PHP using regular expressions?

Examples:

• "hi123" should not be modified.

• "hi 123" should be converted to "hi " .

Answer 1

Use the pattern \b\d+\b where \b matches a word boundary. Here are some tests:

$tests = array(
    'hi123',
    '123hi',
    'hi 123',
    '123'
);
foreach($tests as $test) {
    preg_match('@\b\d+\b@', $test, $match);
    echo sprintf('"%s" -> %s' . "\n", $test, isset($match[0]) ? $match[0] : '(no match)');
}
// "hi123"  -> (no match)
// "123hi"  -> (no match)
// "hi 123" -> 123
// "123"    -> 123

Answer 2

In Ruby (PHP is probably close), I would do it with

string_without_numbers = string.gsub(/\b\d+\b/, '')

where the part between // is the regex and \b indicates a word boundary. Note that this would turn "hi 123 foo" into "hi foo" (note: there should be two spaces between the words). If words are only separated by spaces, you could choose to use

string_without_numbers = string.gsub(/ \d+ /, ' ')

which replaces every sequences of digits surrounded by two spaces with a single space. This may leave numbers at the end of a string, which may not be what you intend.

Answer 3

preg_replace('/ [0-9]+( |$)/S', ' ', 'hi 123 aaa123 123aaa 234');

Answer 4

preg_replace('/ [0-9]+.+/', ' ', $input);

Answer 5

use this regex: regex='\s\d+'