This
dialog
string will fail no matter which quotation mark we choose. Fortunately,
we can escape quotation marks with a backslash (
\
), which is a signal to JavaScript
that the string is not ending. Here’s the preceding example rewritten to use both types
of quotation marks:
const
dialog1
=
"He looked up and said \"don't do that!\" to Max."
;
const
dialog2
=
'He looked up and said "don\'t do that!" to Max.'
;
Then, of course, we get into the chicken-and-egg problem that arises when we want
to use a backslash in our string. To solve this problem, a backslash can escape itself:
const
s
=
"In JavaScript, use \\ as an escape character in strings."
;
Whether you use single or double quotes is up to you. I generally prefer double quo‐
tation marks when I’m writing text that might be presented to the user, because I use
contractions (like don’t) more often than I use double quotation marks. When I’m
expressing HTML inside a JavaScript string, I tend to prefer single quotation marks
so that I can use double quotation marks for attribute values.
Special Characters
The backslash is used for more than simply escaping quotation marks: it is also used
to represent certain nonprintable characters, such as newlines and arbitrary Unicode
characters.
lists the commonly used special characters.
Table 3-1. Commonly used special characters
Code
Description
Example
\n
Newline (technically a line feed character: ASCII/Unicode
10)
"Line1\nLine2"
\r
Carriage return (ASCII/Unicode 13)
"Windows line 1\r\nWindows line 2"
\t
Tab (ASCII/Unicode 9)
"Speed:\t60kph"
\'
Single quote (note that you can use this even when not
necessary)
"Don\'t"
\"
Double quote (note that you can use this even when not
necessary)
'Sam said \"hello\".'
\`
Backtick (or “accent grave”; new in ES6)
`New in ES6: \` strings.`
\$
Dollar sign (new in ES6)
`New in ES6: ${interpolation}`
\\
Backslash
"Use \\\\ to represent \\!"
Special Characters | 41
