Convert double byte integer to single byte-Javascript

Question

Is possible to convert double byte integer to single byte using java script ?? I need to convert double byte numbers as single byte,when it is entered into a text box.Is there any method available in jQuery or javascript.

What do you mean by "convert double byte numbers as single byte..." Leaving aside that JavaScript's numbers are all floating point (that doesn't mean you can't do integer math), if you did that, surely you'd have the problem that double byte (16-bit) integers can store values in the range 0..65,535 (or -32,768..32,767), whereas single byte (8-bit) integers can only store values in the range 0..255 (or -128..127). — T.J. Crowder, Mar 12 '13 at 11:16
I want to convert １２３４ to 1234,The first is doublebyte — Shijin TR, Mar 12 '13 at 11:18

score 4 · Accepted Answer · answered Mar 12 '13 at 11:28

There's no built-in way to convert １ (U+FF11) to 1 (U+0031). You could use a regular expression to do it specifically for the characters you mentioned:

var rex = /[\uFF10-\uFF19]/g;
var str = "１２３４";

console.log("Before: " + str);  
str = str.replace(rex, function(ch) {
    return String.fromCharCode(ch.charCodeAt(0) - 65248);
});

console.log("After: " + str);

Live Example (be sure to open the JavaScript console) | Source

See my answer on how to do it. – silver Apr 28 '14 at 05:35 — silver, Apr 28 '14 at 05:35

score 0 · Answer 2 · answered Apr 25 '14 at 08:41

Why can't you convert it? 65296 is your magic number, the tables never change so just run up and down it and you can convert numbers this way.

This will convert single byte to double byte and back again.

Example requires Jquery but you could write it without quite easy.

<input type="text" id="one" value="1234567890"><br/>
<input type="text" id="two"><br/>
<input type="text" id="three">

<script>
    symbolsToEntities=function(sText){
        var sNewText = "";
        var iLen = sText.length;
        for (i=0; i<iLen; i++){
        iCode = sText.charCodeAt(i);
            sNewText += (iCode > 256? "&#" + iCode + ";": sText.charAt(i));
        };
        return sNewText;
    };

    ConvertNumber=function(num){
        var O='';
        for (var i = 0, len = num.length; i < len; i++){
            O+='&#'+(parseInt(num[i])+65296)+';';
        };
        return O;
    };

    ConvertNumberagain=function(num){
        var O='';
        var res = num.split(';');
        $.each(res, function( key, value ){
            if (value.length!=0){
                O+=parseInt(value.replace('&#',''))-65296;
            };
        });
        return O;
    };
    var doublebyte=ConvertNumber($('#one').val());
    doublebyte = $('<div>').html(doublebyte).text();
    $('#two').val(doublebyte);
    var singlebyte=symbolsToEntities($('#two').val());
    singlebyte=ConvertNumberagain(singlebyte);
    $('#three').val(singlebyte);
</script>

Live example: http://jsfiddle.net/399EM/

Convert double byte integer to single byte-Javascript

2 Answers2