Create new line in javascript

In JavaScript, you can create a new line using the following methods:

Using the \n character:
```
var myString = "Hello\nWorld!";
```
This will create a new line in the string.
Using the <br> tag:
```
var myString = "Hello<br>World!";
```
This will create a new line in the string, but it's not recommended to use HTML tags in JavaScript strings.
Using the String.prototype.split() method:
```
var myString = "Hello World!";
var newLine = myString.split(" ")[1];
```
This will split the string into an array of words, and then extract the second element of the array, which will be the new line.
Using the String.prototype.replace() method:
```
var myString = "Hello World!";
var newLine = myString.replace(/ /g, "\n");
```
This will replace all spaces in the string with new lines.
Using the String.prototype.concat() method:
```
var myString = "Hello";
var newLine = myString.concat("\n", "World!");
```
This will concatenate the string with a new line and another string.

Note that in JavaScript, strings are immutable, so you can't simply add a new line to a string. You need to create a new string with the new line.