Unitter

Simple, versatile unit conversion JS "class"

Setup

Create a new instance of Unitter:

var dataSizeUnitter = new Unitter([
	['bytes', 0.001],
	['KB', 1],
	['MB', 1000],
	['GB', 1000000]
]);

Syntax: new Unitter(unitValues);

• Pass an array of 2-item arrays each representing a unit.
• The first item in each should be a unit string. The second should be that unit's size relative to the base unit's size of 1.
• The array should be sorted by unit size in ascending order.

Parse value

Use the .getValue() method to parse a string with quantity + unit and convert to any desired unit (or the base unit by default):

dataSizeUnitter.getValue('1200 bytes');
    //=> 1.2 (KB = base unit)

Syntax: .getValue(numAndUnit, targetUnit);

• Pass a string with the quantity and unit separated by a space.
• targetUnit defaults to base unit if not passsed.
• Returns the new quantity for the target unit.

Convert to optimal unit

dataSizeUnitter.toUnit('1200 bytes');
    //=> "1.2 KB"

Syntax: .toUnit(num, targetUnit, fromUnit);

• num can be a string ("<quantity> <unit>") such as is passed to .getValue() or a number (in which case, the base unit is assumed if fromUnit is not passed).
• targetUnit defaults to whichever gives a value closest to 1, but it will use any that gives a value >= 1 before resorting to a larger unit that would give a smaller value.