[Stratoscope]

That's incorrect. All of those functions are implemented using iteration.

Consider this excerpt from the .map() polyfill on MDN:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

    // 7. Let k be 0
    k = 0;

    // 8. Repeat, while k < len
    while (k < len) {
      // [loop body omitted]

      // d. Increase k by 1.
      k++;
    }