how to use keydown in javascript code example

Example 1: javascript keydown

document.addEventListener("keydown", function(event) {
  if (event.keyCode == 32) {
    console.log("Space was pressed!");
  }
});

Example 2: javascript onkeydown

<input type="text" onkeydown="myFunction()">

Example 3: keydown events

eventTarget.addEventListener("keydown", event => {
  if (event.isComposing || event.keyCode === 229) {
    return;
  }
  // do something
});

Example 4: event listener for keydown

eventTarget.addEventListener("keydown", event => {
  if (event.isComposing || event.keyCode === 229) {
    return;
  }
  // do something
});