How to check the type of a parameter passed to a function in JavaScript?

Question

I want to make sure that a parameter that is passed to a function is an element and not a number or a string so my program does not crash?

function myFunction(element){ 
  console.log(element.style.color)
}

developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… — 95faf8e76605e973
– 95faf8e76605e973, Commented Jul 27, 2020 at 22:19
You probably want to check more than it not being a number or a string. — evolutionxbox
– evolutionxbox, Commented Jul 27, 2020 at 22:20
in 2020 you can refer it as element?.style?.color . that is the simplest possible way and pretty safe of crashes — Andrei
– Andrei, Commented Jul 27, 2020 at 22:20
You can get some interesting information from param.__proto__.toString() and "" + param.constructor and param.tagName — you can also check if several attributes exist that all Elements will have and (most) other things won't. — Stephen P
– Stephen P, Commented Jul 27, 2020 at 22:34

Ziarno · Accepted Answer · 2020-07-27 23:35:47Z

2

Perhaps you're looking for HTMLElement:

function myFunction(element) {
  if (element instanceof HTMLElement) {
    console.log(element.style.color)
  }
}

answered Jul 27, 2020 at 23:35

Ziarno

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