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JavaScript string Object | Basics

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JavaScript string holds primitive type values which is a sequence of characters. JavaScript treats primitive values as objects when executing methods and properties.

Strings can be created as primitives, from string literals, or as objects, using the String() constructor:

//string literal
const str= "A string primitive";

//string object (using new keyword)
const str= new String("A String object");

So, JavaScript string Object methods and properties (length, substring(), etc). To find the length of a string, use the built-in length property:

Creating Strings:

You can create strings using single or double quotes, or you can use the String constructor:

let str1 = "Hello, World!";
let str2 = 'JavaScript';
let str3 = new String("This is a String Object");


  • length: Returns the length (number of characters) of the string.
let text = "Hello, World!";
console.log(text.length); // Outputs 13

JavaScript string examples

Simple example code strings are created by surrounding them with quotes.

<!DOCTYPE html>
    const n1 = 'Mike';
    const n2 = "Jack";
    const res = `The names are ${n1} and ${n2}`;



JavaScript string Object

Single and double quotes are practically the same, and you can use either.

Backticks are generally used when you need to include variables or expressions into a string. This is done by wrapping variables or expressions with ${variable or expression} as shown above.

The string cannot be changed

You can’t change the strings because JavaScript strings are immutable.

let a = 'hello';
a[0] = 'H';
console.log(a); // "hello"

But you can assign the variable name to a new string.

let a = 'hello';
a = 'Hello';
console.log(a); // "Hello"

Multiline Strings

Use the + operator or the \ operator to get the multiline string.

// 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 Methods

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 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

Do comment if you have any doubts or suggestions on this Js string topic.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

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