​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript 回调</h1>
​
<p>进行计算，然后显示结果。</p>
​
<p id="demo"></p>
​
<script>
function myDisplayer(some) {
  document.getElementById("demo").innerHTML = some;
}
​
function myCalculator(num1, num2, myCallback) {
  let sum = num1 + num2;
  myCallback(sum);
}
​
myCalculator(5, 5, myDisplayer);
</script>
​
</body>
</html>
​