One liner to parse a JavaScript string into a boolean

This ES6 one liner is a handy little JavaScript method for converting a string value into a boolean:


This maps values such as ‘true’, ‘TRUE’ ‘on’, ‘1’, ‘-1’ to true, whilst values such as undefined, null, ‘false’, ‘FALSE’, ‘0’, ‘off’ are treated as false.

View Demo

Here’s a TypeScript version of the same thing:-


and just for completeness, below is the ES5 version