从按钮继承onClick属性

<button onClick="handleClick()">Button 1</button>
<button onClick="handleClick()">Button 2</button>

<script>
function handleClick() {
  alert('Button clicked!');
}
</script>

<!-- index.html -->
<button id="btn1">Button 1</button>
<button id="btn2">Button 2</button>

<script src="script.js"></script>

// script.js
document.getElementById('btn1').onClick = handleClick;
document.getElementById('btn2').onClick = handleClick;

function handleClick() {
  alert('Button clicked!');
}

<button class="clickable-btn">Button 1</button>
<button class="clickable-btn">Button 2</button>

<script>
document.addEventListener('DOMContentLoaded', function() {
  var buttons = document.querySelectorAll('.clickable-btn');
  buttons.forEach(function(button) {
    button.addEventListener('click', handleClick);
  });
});

function handleClick() {
  alert('Button clicked!');
}
</script>

function handleClick(event) {
  alert('Button ' + event.target.id + ' clicked!');
}

var buttons = document.querySelectorAll('.dynamic-btn');
buttons.forEach(function(button) {
  button.addEventListener('click', handleClick);
});