3 Backslash Uses in JavaScript Strings

The skilled JavaScript programmer knows these 3 uses for the backslash character by heart. No need to think. The fingers type the backslash character seemingly automatically in response to the need.

Use 1: Escaping the string delimiter.

JavaScript strings are delimited by either a double- or single-quotation mark. (Either the  "  or  '  character.)

Example:
"Hello, World!"

So how does one use the delimiter character within the string itself? By escaping it with a backslash character.

Example:
"The name is \"Mr. Howdy\""

Use 2: Inserting line feed characters.

In alert messages (for example) line feeds may be desirable to break a line or to insert a blank line. This is done with the backslash-n combination: \n

Example:
"one\ntwo\n\neleven\ntwelve"

The above prints the message as:

one
two

eleven
twelve

\n inserts a line break. \n\n inserts two line breaks, resulting in a blank line.

Use 3: Assigning multi-line strings.

Assigning a string value to a JavaScript variable is generally required to be all one line. A backslash character at the end of the line, however, continues the string on the next line.

Example:
"Row, row, row your boat.\
Gently down the stream."

This article's 3 uses for the backslash character will come in handy time and again as you write JavaScript code.

Here is a function that demonstrates each of the 3 uses:

<script type="text/javascript">
function displayMessage() {

message = "When it rained, I decided to \
read the \"All Things Technical\" book, \
instead of going to the park.\n\nThen the \
sun came out and I unchanged my mind.";

alert(message);
}
</script>

Function displayMessage() is live as an example in this article. Click here to run function displayMessage().

Will Bontrager