# JavaScript Strings

Strings are primitive data type that are used to represent text. They are also one of the most common data types used by JavaScript.

# String Literal

In JavaScript, a string literal is any number of characters (letters, numbers, or special characters) surrounded by a set of quotes (either single or double).

const animal = 'dog'
const phone = '555-555-5555'

# String Concatenation

The term concatenation refers to the combining of two or more strings together. In JavaScript, this is accomplished by use of the plus sign (+) . Concatenation can be used with string literals, numbers and variables.

const greeting = 'Hello, ' + 'world'

const pet = 'dogs'
const number = 3

console.log('I have ' + number + ' ' + pet + '.')

When concatenating, JavaScript will attempt to convert all values to strings. Furthermore, because the plus sign (+) is also use for addition, this can cause unexpected results when working with strings and numbers.

const add = 2 + 1 // 3
const cat = '2' + 1 // 21

String Literals do not support multiple lines, but it is possible to include multiple lines in a string by using the newline special character (\n) and string concatenation.

const title = 'Sherlock Holmes\n' +
'The Hound of the Baskervilles'

# Template Literals

The template literal is a syntax for string literal that allows for embedded expressions and multi-line support. To create a template literal the backtick (`) is used to surrounded the string literal and any expressions.

const greeting = `Hello, World`

Template literals also has multi-line support, which means it possible to include a return inside of a string without the use of the special character or string concatenation.

const address = `
221B Baker Street
London, England`

# Expression Interpolation

Template literal can contain placeholders (${expression}) which are used to embed contain an expressions into a string. Expressions can include variables, formulas or functions.

const name = 'Ted'
const game = `Have you met ${name}?` // Have you met Ted?

const a = 5
const b = 3
const product = `The product of a and b is ${a * b}` // The product of a and b is 8