JavaScript Find Hexadecimal Numbers
From Regex Regular Expression Encyclopedia
This recipe will limit the input to numbers and letters that are valid for hexadecimal representations.
[edit] code
<html> <head> <title></title> </head> <body> <form name="form1"> <input type="textbox" name="txtInput" /> <script type="text/javascript"> function validate() { if (! document.form1.txtInput.value.match(/^[0-9a-f]+$/i)) { alert("Please enter valid value!") } else { alert("Success!") } } </script> <input type="button" name="btnSubmit" onclick="validate()" value="Go" /> </form> </body> </html>
[edit] How It Works
This recipe uses a simple character class to limit the input to digits and the letters a through f:
| Regular Expression | Description |
|---|---|
| ^ | the beginning of the line, followed by . . . |
| [0-9a-f] | a character class that matches the digits zero through nine and the letters |
| \s | a through f . . . |
| + | found one or more times . . . |
| $ | the end of the line. |
Alternatively, you can replace 0-9 in the character class with \d.
