How would you solve this problem before the `let` ?

Question

Hi I'm learning the const and let for making variables. there is a block of code in one of the videos and I'm just curious as to how you would solve that problem in ES5? Here's the code. It's supposed to give an alert every time a button is pressed that says the number of the button. Example Button 1 was pressed or Button 2 was pressed and so on.

const buttons = document.getElementByTagName("button");

for (var i = 0; i < buttons.length; i++) {
    const button = buttons[ i ];
    buttons.addEventListener("click", function() {
        alert("Button " + i + " Pressed");
        })
}

Answer 1 · 2017-12-15T08:07:26Z

December 15, 2017 8:07am

There's a couple of errors in this code, including the spelling of "getElementByTagName" (needs an "s") and the use of "buttons" (plural) where "button" (singular) is needed. But disregarding that for the moment:

Prior to "let", you might resolve the shared variable issue by creating bound functions for the handlers:

  button.addEventListener("click", function (n) {
      alert("Button " + n + " Pressed");
    }.bind(null, i)
  );

Welcome to the Treehouse Community

Looking to learn something new?

SAMUEL LAWRENCE

SAMUEL LAWRENCE

How would you solve this problem before the `let` ?

1 Answer

Steven Parker

Steven Parker

SAMUEL LAWRENCE

SAMUEL LAWRENCE

Steven Parker

Steven Parker

SAMUEL LAWRENCE

SAMUEL LAWRENCE