JavaScript: The Good Parts

Strings

A string literal can be wrapped in single quotes or double quotes. It can contain zero or more characters. The \ (backslash) is the escape character. JavaScript was built at a time when Unicode was a 16-bit character set, so all characters in JavaScript are 16 bits wide.

JavaScript does not have a character type. To represent a character, make a string with just one character in it.

The escape sequences allow for inserting characters into strings that are not normally permitted, such as backslashes, quotes, and control characters. The \u convention allows for specifying character code points numerically.

"A" === "\u0041"

Strings have a length property. For example, "seven".length is 5.

Strings are immutable. Once it is made, a string can never be changed. But it is easy to make a new string by concatenating other strings together with the + operator. Two strings containing exactly the same characters in the same order are considered to be the same string. So:

'c' + 'a' + 't' === 'cat'

is true.

Strings have methods (see Chapter 8):

'cat'.toUpperCase(  ) === 'CAT'