Allow only two special characters (&, - ) in TextBox using JavaScript

EmadKhan

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User: EmadKhan
Posted: on Nov 24, 2016 02:02 AM
Forum: JavaScript
Answer: 1
Views: 17154
Sample Code: Download

Check if string contains any of these characters: `~!@#$%^*()_+={[}];:'",<.>/?\|

If a string contains any of these characters then return false else return true

Please note: In above special characters I have not listed & and - because I want to allow these two special characters.

Please provide regex for both Javascript and C#.

Andrea

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User: Andrea
Replied: on Nov 24, 2016 02:02 AM
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Hi @EmadKhan, Please try the following Regular Expression (Regex) for Alphabets with special characters only It might help you. Cheers Andrea.

AnandM

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User: AnandM
Replied: on Nov 24, 2016 02:26 AM
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Hi EmadKhan,

If you want to allow only & and - special characters then refer below regex which allows only above mentioned characters and check if condition if condition satisfy then return true or return false.

 var regex = /^[&-]$/;

EmadKhan

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User: EmadKhan
Replied: on Nov 24, 2016 02:38 AM
Modified: on Nov 24, 2016 02:40 AM
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No dear,

If I type &a it will give false.... it should only check for the characters I have listed above other characters should be ignored in a string.

Returning TRUE Examples:

Emad & Danish

Khan 123

Correct - Person

Most dangerous / painful event

Returning FALSE Examples:

Emad (khan)

Khan ! is great & Mind blowing

WOW !!! It is amazing and my email is abc@gmail.com

2 + 2 is four

100% is my marks

EmadKhan

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User: EmadKhan
Replied: on Nov 24, 2016 02:43 AM
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Please note:

Dont hard code in regex like a-zA-Z0-9 because a string may contain other languages characters too. Like Germany, Urdu, Chinese .... so that does not contain characters with a-z because those are Unicode characters.

dharmend...

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ANSWER
User: dharmendr
Replied: on Nov 24, 2016 04:17 AM
Modified: on Nov 24, 2016 04:18 AM
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Hi EmadKhan,

Refer the below sample.

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        body
        {
            font-size: 9pt;
            font-family: Arial;
        }
    </style>
    <script type="text/javascript">
        var specialKeys = new Array();
        specialKeys.push(96);  // `
        specialKeys.push(126); // ~
        specialKeys.push(33);  // !
        specialKeys.push(64);  // @
        specialKeys.push(35);  // #
        specialKeys.push(36);  // $
        specialKeys.push(37);  // %
        specialKeys.push(94);  // ^
        specialKeys.push(42);  // *
        specialKeys.push(40);  // ( 
        specialKeys.push(41);  // )
        specialKeys.push(95);  // _ 
        specialKeys.push(61);  // =
        specialKeys.push(43);  // +
        specialKeys.push(91);  // [ 
        specialKeys.push(123); // {
        specialKeys.push(93);  // ] 
        specialKeys.push(125); // }
        specialKeys.push(59);  // ; 
        specialKeys.push(58);  // :
        specialKeys.push(39);  // ' 
        specialKeys.push(34);  // "
        specialKeys.push(44);  // , 
        specialKeys.push(60);  // <
        specialKeys.push(46);  // . 
        specialKeys.push(62);  // >
        specialKeys.push(47);  // / 
        specialKeys.push(63);  // ?
        specialKeys.push(92);  // \ 
        specialKeys.push(124); // |
        function IsSpecificSpecialCharacter(e) {
            var keyCode = e.keyCode == 0 ? e.charCode : e.keyCode;
            var ret = (specialKeys.indexOf(e.keyCode) == -1 && e.charCode == e.keyCode);
            document.getElementById("error").style.display = ret ? "none" : "inline";
            return ret;
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <input name="txtSpecial" type="text" id="txtSpecial" onkeypress="return IsSpecificSpecialCharacter(event);"
            ondrop="return false;" onpaste="return false;" />
        <span id="error" style="color: Red; display: none">* Special Characters not allowed</span>
    </div>
    </form>
</body>
</html>

Allow only two special characters (&, - ) in TextBox using JavaScript

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