In JavaScript, to get the square root of a number we use the Math.sqrt() method.

`var num = Math.sqrt(9);`

The above code would return the number 3.

Some other examples of Math.sqrt() are below:

```
var num = Math.sqrt(1);
var num1 = Math.sqrt(0);
var num2 = Math.sqrt(10);
var num3 = Math.sqrt(196);
var num4 = Math.sqrt(31.3);
var num5 = Math.sqrt(-50);
```

Which would result in the following:

```
1
0
3.1622776601683795
14
5.594640292279746
NaN
```

## JavaScript Square Root in action using jQuery

Below we will provide code to let the user input a number, and then use the **Math.sqrt()** method to find the square root of that number. Here is our simple HTML setup:

```
<p>Type a number you want to use the Math.sqrt() method on below:</p>
<input id="userVal" type="text" value="">
<input id="submitNum" type="submit" value="Submit">
<div id="results"></div>
```

Below is the JavaScript and jQuery code which take the user input using the jQuery **click()** or **on() keypress** methods, and use the Math.sqrt() method on that user input and update the results below using the jQuery **text()** method.

```
$('#userVal').on('keypress',function(e) {
if(e.which == 13) {
$("#results").text(Math.sqrt($("#userVal").val()));
}
});
$("#submitNum").click(function(){
$("#results").text(Math.sqrt($("#userVal").val()));
});
```

The final code and output for this example is below:

Code Output:

Type a number you want to use the Math.sqrt() method on below:

Full Code:

```
<p>Type a number you want to use the Math.sqrt() method on below:</p>
<input id="userVal" type="text" value="">
<input id="submitNum" type="submit" value="Submit">
<div id="results"></div>
<script>
$('#userVal').on('keypress',function(e) {
if(e.which == 13) {
$("#results").text(Math.sqrt($("#userVal").val()));
}
});
$("#submitNum").click(function(){
$("#results").text(Math.sqrt($("#userVal").val()));
});
</script>
```

Hopefully this article has been useful in helping you understand how to find the square root of a number in JavaScript.

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