Creating a JavaScript Function to Multiply Two Numbers

We can use JavaScript to create a function that will multiply two numbers easily. We simply need to use the multiplication operator * in our function. Here is the simple function to multiply two numbers.

function multiplyTwoNumbers(number1,number2){
  return number1*number2;
};

And that’s it.

Our simple function called multiplyTwoNumbers takes two parameters, the two numbers you want to multiply. The function just multiplies them together and then returns the result.

Let’s see some examples of this function in use and the output it produces.

function multiplyTwoNumbers(number1,number2){
  return number1*number2;
};

console.log(multiplyTwoNumbers(2,3));
console.log(multiplyTwoNumbers(-2,3));
console.log(multiplyTwoNumbers(3,2));
console.log(multiplyTwoNumbers(1092,6732));
console.log(multiplyTwoNumbers(-22,-3));
console.log(multiplyTwoNumbers(10002,0));

#Output
6
-6
6
7351344
66
0

Creating a JavaScript Function to Multiply Two Numbers Using User Input

Below is an example of how we can create a function that will multiply two numbers, and then execute the function when a user clicks on a button we create. We will call the JavaScript function we create using an onclick event that we will attach to the HTML button.

<p>Enter two numbers below. Click Submit to have the multiplied value of the numbers displayed:</p>
<input id="userVal1" type="number" value1="">
<input id="userVal2" type="number" value2="">
<button onclick="multiplyNumbers()">Submit</button>
<div id="results"></div>

Below we will write our function. Because the button has the event onclick="multiplyNumbers()", the multiplyNumbers() function, which we will create below, will run when the button is clicked. The function will multiply the two numbers that the user enters together and display the result. If something other than a number is entered, NaN will be returned.

We will retrieve the numbers the user has entered using the value property.

function multiplyNumbers() {
  var num1 = document.getElementById("userVal1").value;
  var num2 = document.getElementById("userVal2").value;
  var total = Number(num1) * Number(num2);
  document.getElementById("results").textContent = total;    
};

The final code and output for this example is below:

Code Output:

Full Code:

<p>Enter two numbers below. Click Submit to have the multiplied value of the numbers displayed:</p>
<input id="userVal1" type="number" value1="">
<input id="userVal2" type="number" value2="">
<button onclick="multiplyNumbers()">Submit</button>
<div id="results"></div>

<script>

function multiplyNumbers() {
  var num1 = document.getElementById("userVal1").value;
  var num2 = document.getElementById("userVal2").value;
  var total = Number(num1) * Number(num2);
  document.getElementById("results").textContent = total;    
};

</script>

Hopefully this article has been useful in helping you learn how to create a JavaScript function to multiply two numbers.