JavaScript Regular Expression Syntax

I am trying to create a regular expression that checks for letters, numbers, and underscores. In .NET, I can do "^\w+$". Ho开发者_如何学JAVAwever, I am not that familiar with the JavaScript syntax. Can somebody help me out?

Thank you!

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One obvious difference is that in JavaScript, you write the regex as /pattern/flags -- this is Perl-style. Your "example" would then be ^\w+$ → /^\w+$/.

For example, replace multiple e's with one e, case-insensitive search (hence the i flag):

var s='qweEEerty';
s=s.replace(/e+/i, 'e');

Returns: qwerty.

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That same expression will work in JavaScript (there are some differences between .NET regular expressions and JavaScript regular expressions but not in this example).

I recommend that you read Using Regular Expressions with JavaScript and ActionScript to learn a bit more about JavaScript's regular expression implementation.