JavaScript String

Strings in JavaScript are basic values. Strings are also permanent. It means that you will always obtain a new string if you edit one. The initial string remains unchanged. 

To create literal strings, you use either single quotes (') or double quotes (") like this:

let str = 'Hi';
let greeting = "Hello";
Code language: JavaScript (javascript)

ES6 introduced template literals that allow you to define a string backtick (`) characters:

let name = `Rocky`';
Code language: JavaScript (javascript)

The template literals allow you to use the single quotes and double quotes inside a string without the need of escaping them. For example:

let mesage = `"I'm good". She said";
Code language: JavaScript (javascript)

Also, you can place the variables and expressions inside a template literal. JavaScript will replace the variables with their value in the string. This is called string interpolation. For example:

let name = 'Rocky';
let message = `Hi, I'm ${name}.`;


Code language: JavaScript (javascript)


Hi, I'm Rocky.

In this example, JavaScript replaces the name variable with its value inside the template literal.

Escaping special characters

To escape special characters, you use the backslash \ character. For example:

  • Windows line break: '\r\n'
  • Unix line break: '\n'
  • Tab: '\t'
  • Backslash '\'

The following example uses the backslash character to escape the single quote character in a string:

let str = 'I\'m a string!';
Code language: JavaScript (javascript)

Getting the length of the string

The length property returns the length of a string:

let str = "Good Morning!";
console.log(str.length); // 13
Code language: JavaScript (javascript)

Note that JavaScript has the String type (with the letter S in uppercase), which is the primitive wrapper type of the primitive string type. Therefore, you can access all properties and methods of the String type from a primitive string.

Accessing characters

Use the array-like [] syntax and the zero-based index to retrieve the characters in a string. The first character of a string with index zero is returned in the example below:

let str = "Hello";
console.log(str[0]); // "H"
Code language: JavaScript (javascript)

To access the last character of the string, you use the length - 1 index:

let str = "Hello";
console.log(str[str.length -1]); // "o"
Code language: JavaScript (javascript)

Concatenating strings via + operator

To concatenate two or more strings, you use the + operator:

let name = 'John';
let str = 'Hello ' + name;

console.log(str); // "Hello Rocky"

Code language: JavaScript (javascript)

If you want to assemble a string piece by piece, you can use the += operator:

let className = 'btn';
className += ' btn-primary'
className += ' none';


Code language: JavaScript (javascript)


btn btn-primary none
Code language: JavaScript (javascript)

Converting values to string

To convert a non-string value to a string, you use one of the following:

  • String(n);
  • ” + n
  • n.toString()

Note that the toString() the method doesn’t work for undefined and null.

When you convert a string to a boolean, you cannot convert it back. For example:

let status = false;
let str = status.toString(); // "false"
let back = Boolean(str); // true
Code language: JavaScript (javascript)

In this example:

  • First, declare the status variable and initialize it with the value of false.
  • Second, convert the status variable to a string using the toString() method.
  • Third, convert the string back to a boolean value using the Boolean() function. The Boolean() function converts the string "false" to a boolean value. The result is true because "false" is a non-empty string.

Note that only string for which the Boolean() returns false, is the empty string ('');

Comparing strings

To compare two strings, you use comparison operators such as >>=<<=, and == operators.

The numeric values of the characters are used by comparison operators to compare strings. Additionally, it might produce a string order that differs from the one seen in dictionaries. For instance:

let result = 'a' < 'b';
console.log(result); // true
Code language: JavaScript (javascript)


let result = 'a' < 'B';
console.log(result); // false
Code language: JavaScript (javascript)

JavaScript Multiline Strings

To use a multiline string, you can either use the + operator or the \ operator. For example,

// using the + operator
const message1 = 'This is a long message ' +
    'that spans across multiple lines' + 
    'in the code.'

// using the \ operator
const message2 = 'This is a long message \
that spans across multiple lines \
in the code.'

JavaScript String Length

To find the length of a string, you can use built-in length property. For example,

const a = 'hello';
console.log(a.length); // 5

JavaScript String Objects

You can also create strings using the new keyword. For example,

const a = 'hello';
const b = new String('hello');

console.log(a); // "hello"
console.log(b); // "hello"

console.log(typeof a); // "string"
console.log(typeof b); // "object"


Note: It is recommended to avoid using string objects. Using string objects slows down the program.

JavaScript String Methods

Here are the commonly used JavaScript String methods:

Method Description
charAt(index) returns the character at the specified index
concat() joins two or more strings
replace() replaces a string with another string
split() converts the string to an array of strings
substr(start, length) returns a part of a string
substring(start,end) returns a part of a string
slice(start, end) returns a part of a string
toLowerCase() returns the passed string in lower case
toUpperCase() returns the passed string in the upper case
trim() removes whitespace from the strings
includes() searches for a string and returns a boolean value
search() searches for a string and returns a position of a match

Example: JavaScript String Methods

const text1 = 'hello';
const text2 = 'world';
const text3 = '     JavaScript    ';

// concatenating two strings
const result1 = text1.concat(' ', text2);
console.log(result1); // "hello world"

// converting the text to uppercase
const result2 = text1.toUpperCase();
console.log(result2); // HELLO

// removing whitespace from the string
const result3 = text3.trim();
console.log(result3); // JavaScript

// converting the string to an array
const result4 = text1.split();
console.log(result4); // ["hello"]

// slicing the string
const result5= text1.slice(1, 3);
console.log(result5); // "el"

JavaScript String() Function

The String() the function is used to convert various data types to strings. For example,

const a = 225; // number
const b = true; // boolean

//converting to string
const result1 = String(a);
const result2 = String(b);

console.log(result1); // "225"
console.log(result2); // "true"

Escape Character

You can use the backslash escape character \ to include special characters in a string. For example 

const name = 'My name is \'Bikash\'.';


My name is 'Bikash'.

In the above program, the same quote is included using \.

Here are other ways that you can use \:

Code Output
\” include double quote
\\ include backslash
\n new line
\r carriage return
\v vertical tab
\t horizontal tab
\b backspace
\f form feed


  • Strings in JavaScript are non – modifiable primitive values.
  • Literal strings are delimited by single quotes ('), double quotes ("), or backticks (`).
  • The length property returns the length of the string.
  • Use the comparison operators `>, >=, <, <=, == to compare strings.

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