Binary to decimal

A simple algorithm to convert a binary string to a decimal number in $O(n)$ time. For each character in the string the result is multiplied by $2$ and if the character is a '1' then $1$ is added to the result. If a non '0' or '1' character is seen the conversion stops.

In real-world Javascript use parseInt(“100101”, 2).

λ binary_to_decimal