Merge pull request #29 from riga/master

Add number-to-bytesize.

Author: blakeembrey

number-to-bytesize/README.md

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+# Number to Bytesize
+
+Convert a number to a string that represents a rounded size in bytes.
+
+## Example
+
+```
+f(156833213) // => '156.83 MB'
+f('8101')    // => '8.1 kB'
+f(12331, 3)  // => '12.331 kB'
+```
+
+By [Riga](https://github.com/riga).

number-to-bytesize/number-to-bytesize.js

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+var prefixes = { Byte: 0, kB: 3, MB: 6, GB: 9, TB: 12, PB: 15, EB: 18 };
+
+var numberToBytesize = function(number, precision) {
+    try {
+        number = parseFloat(number);
+    } catch(e) {
+        return number;
+    }
+
+    var target = 'Byte';
+    var stop = false;
+    Object.keys(prefixes).forEach(function(p) {
+        if(stop)
+            return;
+        if( (number / Math.pow(10, prefixes[p])) >= 1 )
+            target = p;
+        else
+            stop = true;
+    });
+    
+    var factor = Math.pow(10, precision == null ? 2 : precision);
+    var rounded = Math.round((number / Math.pow(10, prefixes[target])) * factor) / factor;
+    return rounded + ' ' + target;
+};