Remove unallowed character from specific pattern in the php

Question

I have a text field in which user can enter any character he/she wants. But in server i have a string patter [a-z0-9][a-z0-9+.-]*, if any of the character in the value from the text box doesn't match the pattern, then i must remove that character from that string. How can i do that in php. is there any functions for that?

Thanks in advance. Gowri Sankar

Answer 1

str_replace('x','',$text);

Answer 2

Just use preg_replace with the allowed pattern negated.

For example, if you allow a to Z and spaces, you simply negate it by adding a ^ to the character class:

echo preg_replace('/[^a-z ]*/i', '', 'This is a String !!!');

The above would output: This is a String (without the exclamation marks).
So it's removing any character that is not a to Z or space, e.g. your pattern negated.

Answer 3

How about:

$string = 'A quick test &*(^&for you this should work';

$searchForThis = '/[^A-Za-z \s]/';

$replaceWithBlank = '';

echo preg_replace($searchForThis, $replaceWithBlank , $string);

Answer 4

.. in PHP we use regular Expressions with preg_replace. Here you have some help with examples... http://www.addedbytes.com/cheat-sheets/regular-expressions-cheat-sheet/

this is what you need:

$new_text = preg_replace('#[^A-Za-z+.-0-9]#s','',$text);

Answer 5

Try this:

$strs = array('+abc123','+.+abc+123','abc&+123','#(&)');
foreach($strs as $str) {
    $str = preg_replace('/(^[^a-z0-9]*)|([^a-z0-9+.-]*)/', '', $str);
    echo "'",$str,"'\n";
}

Output:

'abc123'
'abc+123'
'abc+123'
''