JavaScript In Practice: ES6 And Beyond/

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Tail call optimization

Tail call optimization

tail call optimization for writing elegant recursive solutions without the performance tax of ES5

We'll cover the following...

A tail call is a subroutine call performed as the final action of a procedure. That is,

return myFunction()

It is important to understand that ES6 does not introduce new syntax for tail call optimization. It is just a different structure of code to make sure that it is efficient.

Let’s calculate the Fibonacci using recursion:

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function fib(n) {
  if (n <= 1){
    return n;
  } else {
    return fib(n-1) + fib(n - 2);
  }
}

Let’s view the function calls in the form of a tree:

Notice that none of these have any clue that they are actually a part of a bigger process to calculate fib(5) ...