bitcoincashjs/docs/guide/unit.md

# Unit

## Description

Unit is an utility for handling and converting bitcoin units. We strongly recommend to always use satoshis to represent amount inside your application and only convert them to other units in the front-end.

## Supported units

The supported units are BTC, mBTC, bits (micro BTCs, uBTC) and satoshis. The codes for each unit can be found as members of the Unit class.

```javascript
var btcCode = Unit.BTC;
var mbtcCode = Unit.mBTC;
var ubtcCode = Unit.uBTC;
var bitsCode = Unit.bits;
var satsCode = Unit.satoshis;
```

## Creating units

There are two ways for creating a unit instance. You can instantiate the class using a value and a unit code; alternatively if the unit it's fixed you could you some of the static methods. Check some examples below:

```javascript
var unit;
var amount = 100;

// using a unit code
var unitPreference = Unit.BTC;
unit = new Unit(amount, unitPreference);

// using a known unit
unit = Unit.fromBTC(amount);
unit = Unit.fromMilis(amount);
unit = Unit.fromBits(amount);
unit = Unit.fromSatoshis(amount);
```

## Conversion

Once you have a unit instance, you can check its representantion in all the available units. For your convinience the classes expose three ways to acomplish this. Using the `.to(unitCode)` method, using a fixed unit like `.toSatoshis()` or by using the accessors.

```javascript
var unit;

// using a unit code
var unitPreference = Unit.BTC;
value = Unit.fromSatoshis(amount).to(unitPreference);

// using a known unit
value = Unit.fromBTC(amount).toBTC();
value = Unit.fromBTC(amount).toMilis();
value = Unit.fromBTC(amount).toBits();
value = Unit.fromBTC(amount).toSatoshis();

// using accessors
value = Unit.fromBTC(amount).BTC;
value = Unit.fromBTC(amount).mBTC;
value = Unit.fromBTC(amount).bits;
value = Unit.fromBTC(amount).satoshis;
```