Set Object

The Set object in JavaScript is a collection of unique values, meaning a value can only occur once in a Set. It maintains the order of insertion and allows for any type of value, whether primitive or object references.

• Creation: const set = new Set(); creates an empty set.
• Adding Values: set.add(value); adds a new value to the set.
• Checking Existence: set.has(value); returns true if the value exists in the set.
• Removing Values: set.delete(value); removes the value from the set.
• Size: set.size; returns the number of values in the set.
• Iteration: The Set object can be iterated over using methods like forEach, or using for...of loops on set.keys(), set.values(), and set.entries().

Example Usage

const set = new Set();
set.add('apple');
set.add('banana');
set.add('apple'); // Duplicate, will not be added

console.log(set.has('apple')); // Output: true
console.log(set.size);         // Output: 2

set.delete('banana');
console.log(set.size);         // Output: 1

set.forEach(value => {
  console.log(value);
});
// Output:
// apple

Additional Information

1. Maintaining Order:

   • Sets maintain the order of insertion, which makes iteration predictable.

2. Value Types:

   • Values in a Set can be of any type, including objects, functions, and primitives.

3. Iteration:

   • You can iterate over the values in a Set using methods like for...of with set.values() or set.keys() (which are identical in sets).