How to validate a letter and whitespace only input via JavaScript regular expression

Question

I have an input type="text" for names in my HTML code. I need to make sure that it is a string with letters from 'a' to 'z' and 'A' to 'Z' only, along with space(s).

This is my HTML code:

<form action="" name="f" onsubmit="return f1()">
                Name : <input type="text" name="name">

I'm expecting my JavaScript to be something like this:

function f1() 
{  
   var x=document.f.name.value;  
   ..... 
   ..... 
   return false;
}

PS: I'm not really familiar with Regular Expressions, so please do put up an explanation with the code.

Answer 1

You can use javascript test() method to validate name field. The test() method tests for a match in a string.

/^[A-Za-z\s]+$/.test(x) //returns true if matched, vaidates for a-z and A-Z and white space

or

/^[A-Za-z ]+$/.test(x)

Answer 2

If you are building something for modern browsers, there is something very pleasurable in HTML5:

<input id="username" name="name" type="text" pattern="[a-zA-Z]{5,}" title="Minimum 5 letters" required />

Reference: HTML5 forms input types

Update 2017/01/17:

Old browsers are quite weak on the market shares nowadays. This is a good practice to use HTML5 features instead of compatibility scripts.

Answer 3

check out regular expressions and patterns.

function f1() 
{  
   var x=document.f.name.value;  
   return /^[A-z ]+$/.test(x);
}

Answer 4

["

Here is a longer regx.<\/i>

var reg =  /^[a-zA-Z._-\s{1}\u00C6\u00D0\u018E\u018F\u0190\u0194\u0132\u014A\u0152\u1E9E\u00DE\u01F7\u021C\u00E6\u00F0\u01DD\u0259\u025B\u0263\u0133\u014B\u0153\u0138\u017F\u00DF\u00FE\u01BF\u021D\u0104\u0181\u00C7\u0110\u018A\u0118\u0126\u012E\u0198\u0141\u00D8\u01A0\u015E\u0218\u0162\u021A\u0166\u0172\u01AFY\u0328\u01B3\u0105\u0253\u00E7\u0111\u0257\u0119\u0127\u012F\u0199\u0142\u00F8\u01A1\u015F\u0219\u0163\u021B\u0167\u0173\u01B0y\u0328\u01B4\u00C1\u00C0\u00C2\u00C4\u01CD\u0102\u0100\u00C3\u00C5\u01FA\u0104\u00C6\u01FC\u01E2\u0181\u0106\u010A\u0108\u010C\u00C7\u010E\u1E0C\u0110\u018A\u00D0\u00C9\u00C8\u0116\u00CA\u00CB\u011A\u0114\u0112\u0118\u1EB8\u018E\u018F\u0190\u0120\u011C\u01E6\u011E\u0122\u0194\u00E1\u00E0\u00E2\u00E4\u01CE\u0103\u0101\u00E3\u00E5\u01FB\u0105\u00E6\u01FD\u01E3\u0253\u0107\u010B\u0109\u010D\u00E7\u010F\u1E0D\u0111\u0257\u00F0\u00E9\u00E8\u0117\u00EA\u00EB\u011B\u0115\u0113\u0119\u1EB9\u01DD\u0259\u025B\u0121\u011D\u01E7\u011F\u0123\u0263\u0124\u1E24\u0126I\u00CD\u00CC\u0130\u00CE\u00CF\u01CF\u012C\u012A\u0128\u012E\u1ECA\u0132\u0134\u0136\u0198\u0139\u013B\u0141\u013D\u013F\u02BCN\u0143N\u0308\u0147\u00D1\u0145\u014A\u00D3\u00D2\u00D4\u00D6\u01D1\u014E\u014C\u00D5\u0150\u1ECC\u00D8\u01FE\u01A0\u0152\u0125\u1E25\u0127\u0131\u00ED\u00ECi\u00EE\u00EF\u01D0\u012D\u012B\u0129\u012F\u1ECB\u0133\u0135\u0137\u0199\u0138\u013A\u013C\u0142\u013E\u0140\u0149\u0144n\u0308\u0148\u00F1\u0146\u014B\u00F3\u00F2\u00F4\u00F6\u01D2\u014F\u014D\u00F5\u0151\u1ECD\u00F8\u01FF\u01A1\u0153\u0154\u0158\u0156\u015A\u015C\u0160\u015E\u0218\u1E62\u1E9E\u0164\u0162\u1E6C\u0166\u00DE\u00DA\u00D9\u00DB\u00DC\u01D3\u016C\u016A\u0168\u0170\u016E\u0172\u1EE4\u01AF\u1E82\u1E80\u0174\u1E84\u01F7\u00DD\u1EF2\u0176\u0178\u0232\u1EF8\u01B3\u0179\u017B\u017D\u1E92\u0155\u0159\u0157\u017F\u015B\u015D\u0161\u015F\u0219\u1E63\u00DF\u0165\u0163\u1E6D\u0167\u00FE\u00FA\u00F9\u00FB\u00FC\u01D4\u016D\u016B\u0169\u0171\u016F\u0173\u1EE5\u01B0\u1E83\u1E81\u0175\u1E85\u01BF\u00FD\u1EF3\u0177\u00FF\u0233\u1EF9\u01B4\u017A\u017C\u017E\u1E93]+$/;
                    return reg.test(val);

Answer 5

/^[AZ ]+$/i.test(x) does the trick according to your specification, but if I were you, I'd add dashes, ie /^[-AZ ]+$/i.test(x) , because double-barreled names are quite common. Of course, I'd suggest later revisiting this once JS gets unicode word detection support in its RegExp to support even more names.

EDIT: Actually, if you want to make sure the name is not ill-formed, eg there's at least the first name and the last name and there are no extra spaces, you could do something like this: /^(?:[-AZ]+ )+[-AZ]+$/i.test(x) . I also just remembered you might want to include dots as well, eg "Henry Jr. Jones". Combined to the previous one this would be: /^(?:[-AZ]+\.? )+[-AZ]+$/i.test(x) .

Answer 6

 <!--For Character in Textbox Script -->
    <script type="text/javascript">
        function isAlfa(evt) {
            evt = (evt) ? evt : window.event;
            var charCode = (evt.which) ? evt.which : evt.keyCode;
            if (charCode > 32 && (charCode < 65 || charCode > 90) && (charCode < 97 || charCode > 122)) {
                return false;
            }
            return true;
        }

        function toTitleCase(str) {
            return str.replace(/\w\S*/g, function (txt) {
                return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
            });
        }


    </script>
    <!--For Character in Textbox Script -->

Answer 7

EDIT: Actually, if you want to make sure the name is not ill-formed, eg there's at least the first name and the last name and there are no extra spaces, you could do something like this: /^(?:[-AZ]+ )+[-AZ]+$/i.test(x). I also just remembered you might want to include dots as well, eg "Henry Jr. Jones". Combined to the previous one this would be: /^(?:[-AZ]+.? )+[-AZ]+$/i.test(x).