How to convert string to boolean in typescript Angular 4

Question

I know am not the first to ask this and as I mentioned in my title ,I am trying to convert string value boolean .

I have previously put some values into local storage,No

Answer 1

Define extension: String+Extension.ts

interface String {
  toBoolean(): boolean
}

String.prototype.toBoolean = function (): boolean {
  switch (this) {
    case 'true':
    case '1':
    case 'on':
    case 'yes':
      return true
    default:
      return false
  }
}

And import in any file where you want to use it '@/path/to/String+Extension'