const exp = /^\w{0,3}\W?\s?(\d+)[.,](\d+)?,?(\d+)?$/g
const replacer = (f, group1, group2, group3) => {
return group3 ?
`${group1}${group2}.${group3}` :
`${group1}.${group2}`
}
const usd = '$10.15'.replace(exp, replacer)
const eu = '€01.25'.replace(exp, replacer)
const brl = 'R$ 14.000,32'.replace(exp, replacer)
const tai = 'TAI 50.230,32'.replace(exp, replacer)
const el = document.getElementById('output')
const reverseUSD = new Intl.NumberFormat('en-us', { style: 'currency', currency: 'USD' }).format(usd)
el.innerHTML += `<br> from: ${reverseUSD} to ${parseFloat(usd)}`
const reverseBRL = new Intl.NumberFormat('pt-br', { style: 'currency', currency: 'BRL' }).format(brl)
el.innerHTML += `<br> from: ${reverseBRL} to ${parseFloat(brl)}`
const reverseTAI = new Intl.NumberFormat('en-us', { style: 'currency', currency: 'TAI' }).format(tai)
el.innerHTML += `<br> from: ${reverseTAI} to ${parseFloat(tai)}`
const reverseEU = new Intl.NumberFormat('eur', { style: 'currency', currency: 'EUR' }).format(eu)
el.innerHTML += `<br> from: ${reverseEU} to ${parseFloat(eu)}`
<output id=output></output>