JAVASCRIPT PLZ

Write a Function named octalToDecimal that performs octal to decimal conversion. When invoked on a String that contains the representation of an octal number, the Function returns a decimal version of that value as a Number. Implement the conversion yourself: do not use something else to perform the conversion for you.

EXAMPLE:

octalToDecimal('1'); // 1 octalToDecimal('10'); // 8 octalToDecimal('130'); // 88 octalToDecimal('17'); // 15 octalToDecimal('2047'); // 1063 octalToDecimal('11'); // 9