Suppose I want to convert a base-36 encoded string to a BigInt
, I can do this:
BigInt(parseInt(x,36))
But what if my string exceeds what can safely fit in a Number? e.g.
parseInt('zzzzzzzzzzzzz',36)
Then I start losing precision.
Are there any methods for parsing directly into a BigInt
?
You could convert the number to a bigint
type.
function convert(value, radix) {
return [...value.toString()]
.reduce((r, v) => r * BigInt(radix) + BigInt(parseInt(v, radix)), 0n);
}
console.log(convert('zzzzzzzzzzzzz', 36).toString());
With greater chunks, like just for example with ten (eleven return a false result).
function convert(value, radix) { // value: string
var size = 10,
factor = BigInt(radix ** size),
i = value.length % size || size,
parts = [value.slice(0, i)];
while (i < value.length) parts.push(value.slice(i, i += size));
return parts.reduce((r, v) => r * factor + BigInt(parseInt(v, radix)), 0n);
}
console.log(convert('zzzzzzzzzzzzz', 36).toString());