I would like to write the function which takes file size in bytes(7762432) and return value in user readable format (7,762,432 bytes).

function(fileSizeBytes){
    // mind blowing logic :)
    return userReadable;
}

I have done it using old school string split way, but i am just curious if there exist way that can blow my head and make me scream with "O god it can be done this way too !!"

I would like to write the function which takes file size in bytes(7762432) and return value in user readable format (7,762,432 bytes).

function(fileSizeBytes){
    // mind blowing logic :)
    return userReadable;
}

I have done it using old school string split way, but i am just curious if there exist way that can blow my head and make me scream with "O god it can be done this way too !!"

• javascript

8 Answers 8

function addCommas(value) {
    var regex = /^(\d+)(\d{3}[\.]?.*)$/;
    while (regex.exec(value)) {
        value= RegExp.$1
                ? RegExp.$1 + ',' + RegExp.$2
                : RegExp.$2;
    }
    return value;
}

one line function:

function formatFileSizeBytes(size) {
    return size.replace(/(\d)(?=(\d{3})+$)/g, "$1,");
}

some testing:

for (var i = 0; i <= "123456789".split('').length; i++) {  
    alert(formatFileSizeBytes(a.slice(0,i).join(''))); 
}

One liner:

function(fileSizeBytes){
    return fileSizeBytes.toString(10).split('').reverse().join('').replace(/(...)/g,'$1,').replace(/,$/,'').split('').reverse().join('') + ' bytes';
}

Ok, there should be some ENTERPRISE solution for this with intensive i18n support

var numberLocaleFormat = (function() {
  var cache = {};
  return (function (separator, grouping, groupingAdd) {
    separator = separator || ",";
    grouping = grouping || 3;
    groupingAdd = groupingAdd || grouping;
    var key = grouping + "+" + groupingAdd + "/" + separator;
    if (key in cache) return cache[key];
    return (cache[key] = function(number){
      var str = [], number = number.toString();
      var separatorIndex = grouping;
      for (var i = number.length-1, idx = 0; i >= 0; i--, idx++) {
        str.push(number.charAt(i));
        if ((idx == separatorIndex-1) && i) {
           separatorIndex += groupingAdd;
           str.push(separator);
        }
      }
      return str.reverse().join('');
    });
  });
})();

Usage:

numberLocaleFormat()(1234578); // "12,345,678", America
numberLocaleFormat(" ")(12345678); // "12 345 678", Europe
numberLocaleFormat(",",4)(12345678); // "1234,5678", Japan
numberLocaleFormat(",", 3, 2)(12345678); // "1,23,45,678", India

I wrote this function four years ago:

function formatNumber(x) { 
    if(!isFinite(x)) return x.toString();
    var str         = Math.abs(x).toString();
    if(str.indexOf("e") != -1) return x.toString();
    var decimalPos  = str.indexOf(".");
    var decimal;

    if(decimalPos == -1)
        decimal = "";
    else {
        decimal = str.substring(decimalPos);
        str = str.substring(0, decimalPos);
    }
    if(str.length < 4) return x.toString();

    var start = str.substr(0, str.length % 3);
    if(start.length != 0) {
        str = str.substr(start.length)
        start += ",";
    }
    if(x < 0) start = "-" + start;

    var segments = new Array(Math.ceil(str.length / 3.0));
    for(var i = 0; i < str.length; i += 3) {
        segments[i / 3] = str.substr(i, 3);
    }

    return start + segments.join() + decimal;
};

How about using the php.js library?? number_format() function.. the doc says that the function is standalone

=P i wont break my head to do something that's already done

In Internet Explorer and Firefox, you can do return Number(fileSizeBytes).toLocaleString();.

Unfortunately, Google Chrome, Safari and Opera don’t play nice with this. They just return the same as toString().

This one should work if you have restriction on using an array or regex.

function ma_separate(num) {
    var ma = Math.floor((num.length) / 3);
    var offset = (num.length) % 3;
    var result = '';
    if(offset > 0) {
        result = num.substr(0,offset);
    }

    for(var i=0; i<ma; i++) {
        result = result ? result + ',' : '';
        result = result + num.substr(i*3,3);
    }

    return result;
}

tested here