JavaScript set add() method explanation with example

JavaScript set add() method explanation with example:

JavaScript Set provides a method called add(), by using which we can add one element to a set. JavaScript Set object can be used to hold unique values of any type.

We can create a new set object by using its constructor Set(). Once created, we can add elements to this object by using the add() method.

Definition of add():

add is an instance method of Set and this method is used to append a new element with a specific value to the end.

This method returns a Set object.

The syntax of add is:

set.add(value);

value is the value to add to the set.

Example of add() method:

Let’s take an example of add and how to use it:

let givenSet = new Set();

givenSet.add('hello');
givenSet.add(' ');
givenSet.add('world');

console.log(givenSet);

for(const element of givenSet){
    console.log(element);
}

It will print the below output:

Set(3) { 'hello', ' ', 'world' }
hello
 
world

As you can see here, add retuns a Set object. So, we can use it in a chain:

let givenSet = new Set();

givenSet.add('hello').add(' ').add('world');

console.log(givenSet);

for(const element of givenSet){
    console.log(element);
}

It will print the same output.

Add the same item multiple times:

If we try to add the same item for multiple times, it will not add that item. Because, a set can hold only unique values. For example,

let givenSet = new Set();

givenSet.add('hello').add(' ').add('world').add('hello').add('world');

console.log(givenSet);

It will print:

Set(3) { 'hello', ' ', 'world' }

As you can see here, it is not adding the same string twice.

Example with numbers:

We can also use Set with numbers. For example,

let givenSet = new Set();

givenSet.add(1).add(2).add(3).add(4).add(5).add(6).add(7).add(8).add(9).add(10);

console.log(givenSet);

It is adding numbers from 1 to 100 to the Set givenSet.

It will print:

Set(10) { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }

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JavaScript set add() method explanation with example