Javascript: indexOf with Regular Expression

Question

How can I check whether the page url contains a '#' character plus some random digits

e.g. www.google.de/#1234

if( window.location.href.indexOf('#') > 0 ){
  alert('true');
}

Does indexOf support Regular Expressions?

Bookmobile

Why do you need to know the index of it? Just use the .match() function to test if the regexp matches? – Salmagundi

Can't you just test what's in window.location.hash? – Salmagundi

Answer 1

Use String.prototype.search to get the index of a regex:

'https://example.com/#1234'.search(/#\d+$/); // 20

And RegExp.prototype.test if used for boolean checks:

/#\d+$/.test('https://example.com/#1234'); // true

The regex used for these examples are /#\d+$/ which will match literal # followed by 1 or more digits at the end of the string.

As pointed out in the comments you might just want to check location.hash:

/^#\d+$/.test(location.hash);

/^#\d+$/ will match a hash that contains 1 or more digits and nothing else.

Shutin

Thank you very much for the detailed explanation. – Bookmobile