String

• Primitive types don't have properties and methods, only objects do.
• In JavaScript you have two kinds of string one is string primitive and other is string object.
• String object is created using String constructor function

//Primitive
const message1 = "hello";
//Object
const message2 = new String("hello");

• When you use the dot notation with a string primitive JavaScript engine internally wraps this with a string object,

Important Properties

• length

Important Methods

Some method returns new string

• includes
• startsWith
• endsWith
• indexOf
• replace
• substr
• split
• toUpperCase
• toLowerCase
• trim
• trimLeft
• trimRight

Escape sequences

• Special characters can be encoded using escape sequences

const message1 = 'This is Krishna\'s  book ';
const message2 = 'first line \n second line';

String Concatenation

• Use + to concatenate strings

const name = "ganesh";
const age = 30;
const message = "Hi, I am " + name + ", aged " + age;

Multi Line Strings (Old Format)

const multiline = "first line \n" +
"second line \n" +
"third line";

Template Literals

• Use back ticks to create template literals
• You can create multi-line strings
• You can add placeholders/variables inside template literals. The placeholder can be a valid JavaScript expression

Multiline

const multiline = `first line
second line
third line
`;

Interpolation

• Automatic replacing of expressions with real values is called string interpolation.

const name = "ganesh";
const age = 30;
const message = `Hi, I am ${name}, aged {age}`;