How to accurately add extrinsic balance transfer values

Question

Is there a simpler way to add balance transfer values without converting them to BN or Unit value first? For example, say I want to add "0x00000000000000001bc16d674ec80000", "0x000000000000021e19e0c9bab2400000" and "0x00000000000000000de0b6b3a7640000" which in units are "2.0000 Unit", "10.0000 kUnit", and "1.0000 Unit".

I have used @polkadot/util 's formatBalance with forceUnit option to get uniform units and then add. But I feel like there may be a better way.

Answer 1

I'm assuming the above are hex strings? In that case you would need to convert and add them.

import { hexToBn } from '@polkadot/util';

// convert and add
const total = hexToBn('0x00000000000000001bc16d674ec80000')
  .add(hexToBn('0x000000000000021e19e0c9bab2400000'))
  .add(hexToBn('0x00000000000000000de0b6b3a7640000'));

// format as needed