js

Set

The Set object holds only unique values of any type.

Standard built-in objects

• Set() constructor
• Set::add()
• Set::clear()
• Set::delete()
• Set::difference()
• Set::entries()
• Set::forEach()
• Set::has()
• Set::intersection()
• Set::isDisjointFrom()
• Set::isSubsetOf()
• Set::isSupersetOf()
• Set::keys()
• Set::symmetricDifference()
• Set::union()
• Set::values()
• Set::size

Constructor

new Set()

Creates a new Set object.

$set = new Set(['foo', 'bar', 'foo']);
// ['foo', 'bar']

Static methods

Methods

Set::add()

The add() method adds a new element in to Set.

$set = new Set();

$set->add(40);
// [40]

$set->add('first')->add('second');
// [40, 'first', 'second']

Values are always unique.

$set = new Set();

$set->add(40);
// [40]

$set->add('first')->add('second');
// [40, 'first', 'second']

$set->add(40)->add('second');
// [40, 'first', 'second']

Set::clear()

The clear() method removes all elements from the Set.

$set = new Set(['foo', 'bar']);

$set->size;
// 2

$set->clear();

$set->size;
// 0

Set::delete()

The delete() method removes a specified value from the Set.

$set = new Set(['foo', 'bar']);

$set->delete('foo');
// true

$set->delete(1);
// false

Set::difference()

The difference() method returns a new Set containing elements in this Set but not in the given Set.

$odds = new Set([1, 3, 5, 7, 9]);
$squares = new Set([1, 4, 9]);

$set->difference($squares);
// Set[3, 5, 7]

Set::entries()

The entries() method returns a new SetIterator instance that contain pair array [value, value] of each element of the Set.

$set = new Set(['foo', 'bar']);

$iterator = $set->entries();
// [object SetIterator]

$iterator->current();
// ['foo', ''foo']

Set::forEach()

The forEach() method executes a provided function once per each element of the Set.

$set = new Set([3, 0]);

$set->forEach(function (int $value1, int $value2, Set $set) {
    // ...
});

Set::has()

The has() method returns TRUE when element with the specified value exists in the Set or FALSE if it does not exist.

$set = new Set([1, 2, 3, 4, 5]);

$set->has(1);
// true

$set->has(6);
// false

Set::intersection()

The intersection() method returns a new set containing only those elements that exist in both sets.

$odds = new Set([1, 3, 5, 7, 9]);
$squares = new Set([1, 4, 9]);

$odds->intersection($squares);
// Set[1, 9]

Set::isDisjointFrom()

The isDisjointFrom() method checks if Set has no elements in common with the given Set.

$primes = new Set([2, 3, 5, 7, 11, 13, 17, 19]);
$squares = new Set([1, 4, 9, 16]);

$primes->isDisjointFrom($squares);
// true

Set::isSubsetOf()

The isSubsetOf() method checks if all elements of a Set are in a given Set.

$fours = new Set([4, 8, 12, 16]);
$evens = new Set([2, 4, 6, 8, 10, 12, 14, 16, 18]);

$fours->isSubsetOf($evens);
// true

Set::isSupersetOf()

The isSupersetOf() method checks if all elements of the given Set are in the Set.

$evens = new Set([2, 4, 6, 8, 10, 12, 14, 16, 18]);
$fours = new Set([4, 8, 12, 16]);

$evens->isSupersetOf($fours);
// true

Set::keys()

The keys() method is exactly equivalent to the values() method.

$set = new Set(['foo' => 'bar']);

$iterator = $set->keys();
// [object SetIterator]

$iterator->current();
// 'foo'

Set::symmetricDifference()

The symmetricDifference() method returns a new Set containing elements that not in both Sets.

$evens = new Set([2, 4, 6, 8]);
$squares = new Set([1, 4, 9]);

$evens->symmetricDifference($squares);
// Set[2, 6, 8, 1, 9 ]

Set::union()

The union() method returns a new Set containing all elements from both Sets.

$odds = new Set([1, 3, 5, 7, 9]);
$squares = new Set([1, 4, 9]);

$odds->union($squares);
// Set[1, 3, 5, 7, 9, 4]

Set::values()

The values() method returns a new SetIterator instance that contain the values of each element of the Set.

$set = new Set(['foo', 'bar']);

$iterator = $set->values();
// [object SetIterator]

$iterator->current();
// 'foo'

$iterator->next();
// 'bar'

Properties

Set::size

The size property returns number of elements from the Set.

$set = new Set(['foo', 'bar']);

$set->size;
// 2

$set->delete('foo');
$set->size;
// 1