Javascript Getting a string into kb format

Question

I am new to javascript and I just wanted to convert a string into a format that a person like me can read. Here is an example of what I am trying to do...

string2size(string){ //some awesome coding I have no clue how to make return awesomeAnswer }

now the return should give me something like 56 bytes or 12kb or 1mb depending how much the string is.

so if the string is... string = "there was an old woman who lived in a shoe"; then string2size(string) should return something like 3kb.

Now I know there has been a utf8 talk and I wouldn't object to and addition of that to the function.

I have tried google and Yahoo searches but they talk of using php but I really need it for javascript. I do thank anyone for their time. -Teske

Answer 1

First list the units you want to use. For example:

// 1024-based units. Kibibyte, Mebibyte etc.
//
var BINARY_UNITS= [1024, 'Ki', 'Mi', 'Gi', 'Ti', 'Pi', 'Ei', 'Zi', 'Yo'];

// SI units, also Hard Disc Manufacturers' rip-off kilobytes
//
var SI_UNITS= [1000, 'k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];

Then make a function to find and divide by the biggest suitable unit for a number:

function unitify(n, units) {
    for (var i= units.length; i-->1;) {
        var unit= Math.pow(units[0], i);
        if (n>=unit)
            return Math.floor(n/unit)+units[i];
    }
    return n; // no prefix, single units
}

Then call on a length:

var desc= 'File, '+unitify(content.length, UNITS_BINARY)+'B';
desc+= ' or in SI, '+unitify(content.length, UNITS_SI)+'B';

// eg. File, 977KiB or in SI 1MB

I'm not sure what you mean with UTF-8, but if you want to find out the length of a character string as encoded to bytes you'll have to encode that string to UTF-8 yourself. Luckily there is a cheap trick to get a UTF-8 encoder in JavaScript:

var bytes= unescape(encodeURIComponent(chars));
alert(unitify(bytes, BINARY_UNITS)+'B');

Answer 2

Super It is what I wanted... Thank You!!!!