JavaScript Program to Calculate with Two Input Numbers

The question

Create two number inputs with ids "a" and "b", a button with id "calc" and a <span id="result">. When the button is clicked, show the product of the two numbers in #result (only the number).

The code

<input type="number" id="a">
<input type="number" id="b">
<button id="calc">Calculate</button>
<p>Result: <span id="result"></span></p>

<script>
document.getElementById("calc").addEventListener("click", function () {
  var a = Number(document.getElementById("a").value);
  var b = Number(document.getElementById("b").value);
  document.getElementById("result").textContent = a * b;
});
</script>

Result

How it works

1. 1document.getElementById("a").value reads what was typed in the first box.
2. 2Number(…) converts that text into a number.
3. 3The result is written into the #result span with textContent.