JavaScript Power Operator

In JavaScript, the Power Operator, or exponentiation operator, **, is used to raise a number to the power of an exponent.

var num = 2**4;

The output of the code above would be the number 16.

Some other examples of the power operator are below:

var num1 = 6**1;
var num2 = 2**2;
var num3 = 3**25;
var num4 = 0**3;
var num5 = (-2)**2;
var num6 = (-2)**3;
var num7 = (-2)**-2;
var num8 = (-2)**-3;
var num9 = 3**0;
var num10 = .3**4;

This would result in the following:

6
4
847288609443
0
4
-8
0.25
-0.125
1
0.0081

One main thing to be aware of is that any negative base number will need to be in parentheses. So (-2)**2 and not -2**2.

Note that we can also use the Math.pow() method to get the same result.

var num = Math.pow(2,4);

The output of the code above would again be the number 16.

Let’s see the examples above using the Math.pow() method:

var num1 = Math.pow(6,1);
var num2 = Math.pow(2,2);
var num3 = Math.pow(3,25);
var num4 = Math.pow(0,3);
var num5 = Math.pow(-2,2);
var num6 = Math.pow(-2,3);
var num7 = Math.pow(-2,-2);
var num8 = Math.pow(-2,-3);
var num9 = Math.pow(3,0);
var num10 = Math.pow(.3,4);

They result in the same output as we had using the power operator above:

6
4
847288609443
0
4
-8
0.25
-0.125
1
0.0081

JavaScript Power Operator in Action

Below we will provide code to let the user input two numbers, and then use the power operator to find the first number(base) to the power of the second number(exponent). Here is our simple HTML setup:

<p>Enter two numbers below. We will provide the result of the first number to the power of the second number.</p>
<input id="userVal1" type="number" value1="">
<input id="userVal2" type="number" value2="">
<button onclick="runFunction()">Submit</button>
<div id="results"></div>

Below we will write our function. We will get both numbers that the user has entered using the value property. We will then display the results using the textContent property.

function runFunction() {
  var num1 = document.getElementById("userVal1").value;
  var num2 = document.getElementById("userVal2").value;
  if( num1 < 0 ){
    var num = (Number(num1))**Number(num2);
  } else {
    var num = Number(num1)**Number(num2);
  }
  document.getElementById("results").textContent = num;    
}

The final code and output for this example is below:

Code Output:

Full Code:

<p>Enter two numbers below. We will provide the result of the first number to the power of the second number.</p>
<input id="userVal1" type="number" value1="">
<input id="userVal2" type="number" value2="">
<button onclick="runFunction()">Submit</button>
<div id="results"></div>

<script>

function runFunction() {
  var num1 = document.getElementById("userVal1").value;
  var num2 = document.getElementById("userVal2").value;
  if( num1 < 0 ){
    var num = (Number(num1))**Number(num2);
  } else {
    var num = Number(num1)**Number(num2);
  }
  document.getElementById("results").textContent = num;    
}

</script>

Hopefully this article has been useful in helping you learn about JavaScript Power Operator.