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// Perfectly valid because in JavaScript you can access characters in a string by index
// example:
//    const x = 'coffee'
//    const letterF = x[3]   // result: 'f'
const result = something('hello', 50)

// NOT valid because in JavaScript you can't access characters in a string by a string
const result = something('hello', '50')

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const result = something({ goodwill: 'a' }, 'toString')

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// Completely valid -- TypeScript will not complain
const result = something({ goodwill: 'a' }, 'goodwill')

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function something<T, K extends keyof T>(arg1: T, arg2: K) {
  //
}

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function combine<T, W>(arg1: W, arg2: T): T {
  return arg2
}

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function combine(arg1: string, arg2: string): string {
  return arg2
}

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function combine<T, W>(arg1: W, arg2: T): T {
  return arg2
}

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let fruit = 'apple'

function sayStuff(stuff) {
  window.alert(stuff)
}

sayStuff(`i love eating ${fruit}s`) // implicit
// or
sayStuff < number > 500 // explicit

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function logAndReturnIt<T>(
  valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction: T,
): T {
  console.log(typeof valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction)
  
  return valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction
}

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function logAndReturnIt(
  valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction: any,
): any {
  console.log(typeof valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction)
  
  return valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction
}

logAndReturnIt(null) // valid
logAndReturnIt(5) // valid