PHP Regex to allow special characters but no any space - php

Question

I have the following Regex to allow alphanumeric characters and following special characters
/()-
The Regular expression is
/[^A-Za-z0-9-()-/]/
The complete method is
public function ValidateNumber($number)
{
$return = true;
$matches = null;
if((preg_match('/[^A-Za-z0-9-/()-]/', $number, $matches)) > 0)
{
$return = false;
}
return $return;
}
Above method woks fine, but also return TRUE if number has space. When i remove '/' from Regex then if number has 'space' in it then it returns FALSE.
So seems some issue with '/' in Regex.
Please advise some solution

Answer 1

Use this:
$theregex = '~^[a-z0-9/()-]+$~i';
if (preg_match($theregex, $yourstring)) {
// Yes! It matches!
}
else { // nah, no luck...
}
Explanation
The i flag at the end makes it case-insensitive
The ^ anchor asserts that we are at the beginning of the string
To match a hyphen in a [character class], place it at the beginning or at the end so that it is not ambiguous, since it may indicate a range, as in a-d
[a-z0-9/()-]+ matches one or more letter, digit, slash, parenthesis or hyphen
The $ anchor asserts that we are at the end of the string

Answer 2

Regex to allow alphanumeric characters and the the above mentioned special characters /()-,
^[A-Za-z0-9()\/-]+$
^ inside(at the strat of) chracter class means not. So your regex allows any character not of the ones mentioned inside the character class. And also it's better to escape / inside the character class and always consider in putting - at the start or end of the character class. To allow one ore more characters which was mentioned inside char class then you need to add + after the character class.
Explanation:
^ the beginning of the string
[A-Za-z0-9()\/-]+ any character of: 'A' to 'Z', 'a' to 'z',
'0' to '9', '(', ')', '\/', '-' (1 or more
times)
$ before an optional \n, and the end of the
string

Answer 3

You should escape / in your regex using \/
But you should probably use the following expression to do what you want:
([^A-Za-z0-9-()-\/])+
So the whole method could look like this:
public function ValidateNumber($number)
{
if (preg_match('/([^A-Za-z0-9-()-\/])+/', $number)) {
return false;
}
return true;
}
without extra variables.
In above case you try to find any characters that don't match (here ^ means characters that don't match) your criteria and if any of them is found preg_match return 1 so it means that number is invalid.
However you can also use another expression to achieve what you want - you don't find characters that don't match (as in previous example) but you check if the whole string matches your criteria using ^ as the beginning (in this case it means the beginning of the string - meaning is different that the one in previous solution) and $ as the end of the string to check the whole string. In this case your method could look like this:
public function ValidateNumber($number)
{
if (preg_match('/^([A-Za-z0-9-()-\/]+)$/', $number)) {
return true;
}
return false;
}

Answer 4

For Much better understanding and learning regex for the further work you can visit the below links
Learning Regular Expressions
Useful regular expression tutorial
Regular expressions tutorials
And one of the best and easy one and my favourite is
http://www.9lessons.info/2013/10/understanding-regular-expression.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+9lesson+%289lessons%29
very nice and easy tutorial for the beginners