How do I format bytes to human readable text in javascript? - Stack Overflow

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I'm trying to convert a file size represented in bytes in JavaScript as follows (HTML 5).

function formatBytes(bytes)
{
    var sizes = ['Bytes', 'kB', 'MB', 'GB', 'TB'];
    if (bytes == 0) 
    {
        return 'n/a';
    }
    var i = parseInt(Math.log(bytes) / Math.log(1024));
    return Math.round(bytes / Math.pow(1024, i), 2) + sizes[i];
}

But I need to represent the file size in both SI and binary units as and when required like,

kB<--->KiB
MB<--->MiB
GB<--->GiB
TB<--->TiB
EB<--->EiB

This could be done in Java like the following (using one additional boolean parameter to the method).

public static String formatBytes(long size, boolean si)
{
    final int unitValue = si ? 1000 : 1024;
    if (size < unitValue) 
    {
        return size + " B";
    }
    int exp = (int) (Math.log(size) / Math.log(unitValue));
    String initLetter = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
    return String.format("%.1f %sB", size / Math.pow(unitValue, exp), initLetter);
}

Somewhat equivalent code in JavaScript could be as follows.

function formatBytes(size, si)
{
    var unitValue = si ? 1000 : 1024;
    if (size < unitValue) 
    {
        return size + " B";
    }
    var exp = parseInt((Math.log(size) / Math.log(unitValue)));
    var initLetter = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
    alert(size / Math.pow(unitValue, exp)+initLetter);
    //return String.format("%.1f %sB", size / Math.pow(unitValue, exp), initLetter);
}

I couldn't write the equivalent statement in JavaScript as the mented line in the preceding snippet (the last one) indicates. Of course, there are other ways to do this in JavaScript but I'm looking for a concise way and more precisely, if it is possible to write the equivalent statement in JavaScript/jQuery. Is it possible?

I'm trying to convert a file size represented in bytes in JavaScript as follows (HTML 5).

function formatBytes(bytes)
{
    var sizes = ['Bytes', 'kB', 'MB', 'GB', 'TB'];
    if (bytes == 0) 
    {
        return 'n/a';
    }
    var i = parseInt(Math.log(bytes) / Math.log(1024));
    return Math.round(bytes / Math.pow(1024, i), 2) + sizes[i];
}

But I need to represent the file size in both SI and binary units as and when required like,

kB<--->KiB
MB<--->MiB
GB<--->GiB
TB<--->TiB
EB<--->EiB

This could be done in Java like the following (using one additional boolean parameter to the method).

public static String formatBytes(long size, boolean si)
{
    final int unitValue = si ? 1000 : 1024;
    if (size < unitValue) 
    {
        return size + " B";
    }
    int exp = (int) (Math.log(size) / Math.log(unitValue));
    String initLetter = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
    return String.format("%.1f %sB", size / Math.pow(unitValue, exp), initLetter);
}

Somewhat equivalent code in JavaScript could be as follows.

function formatBytes(size, si)
{
    var unitValue = si ? 1000 : 1024;
    if (size < unitValue) 
    {
        return size + " B";
    }
    var exp = parseInt((Math.log(size) / Math.log(unitValue)));
    var initLetter = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
    alert(size / Math.pow(unitValue, exp)+initLetter);
    //return String.format("%.1f %sB", size / Math.pow(unitValue, exp), initLetter);
}

I couldn't write the equivalent statement in JavaScript as the mented line in the preceding snippet (the last one) indicates. Of course, there are other ways to do this in JavaScript but I'm looking for a concise way and more precisely, if it is possible to write the equivalent statement in JavaScript/jQuery. Is it possible?

• javascript

Share Improve this question Follow edited Oct 10, 2016 at 23:03 KingKongFrog 14.4k2222 gold badges7676 silver badges131131 bronze badges asked Apr 15, 2013 at 20:03 TinyTiny 28k112112 gold badges351351 silver badges608608 bronze badges 3

• possible duplicate of Equivalent of String.format in JQuery – Mike Samuel Commented Apr 15, 2013 at 20:06
• @Mike Samuel : I have seen that question before asking this one but that question is mostly related to ASP.NET. – Tiny Commented Apr 15, 2013 at 20:12
• converting sprintf style format strings to the String.format convention should be trivial since the only format you use is .1f which can be handled via myNumber.toFixed(1). – Mike Samuel Commented Apr 15, 2013 at 20:21

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 9

http://jsbin./otecul/1/edit

function humanFileSize(bytes, si) {
    var thresh = si ? 1000 : 1024;
    if(bytes < thresh) return bytes + ' B';
    var units = si ? ['kB','MB','GB','TB','PB','EB','ZB','YB'] : ['KiB','MiB','GiB','TiB','PiB','EiB','ZiB','YiB'];
    var u = -1;
    do {
        bytes /= thresh;
        ++u;
    } while(bytes >= thresh);
    return bytes.toFixed(1)+' '+units[u];
};

humanFileSize(6583748758); //6.1 GiB
humanFileSize(6583748758,1) //6.4 GB

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