The Set class

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The Set class


(No version information available, might only be in Git)

A Set is a sequence of unique values. This implementation uses the same hash table as Ds\Map, where values are used as keys and the mapped value is ignored.


  • Values can be any type, including objects.
  • Supports array syntax (square brackets).
  • Insertion order is preserved.
  • Automatically frees allocated memory when its size drops low enough.
  • add(), remove() and contains() are all O(1).


  • Doesn’t support push(), pop(), insert(), shift(), or unshift().
  • get() is O(n) if there are deleted values in the buffer before the accessed index, O(1) otherwise.

Class synopsis

class Ds\Set implements Ds\Collection, ArrayAccess {

/* Constants */

const int MIN_CAPACITY = 16;

/* Methods */

public add(mixed ...$values): void
public allocate(int $capacity): void
public capacity(): int
public clear(): void
public contains(mixed ...$values): bool
public copy(): Ds\Set
public diff(Ds\Set $set): Ds\Set
public filter(callable $callback = ?): Ds\Set
public first(): mixed
public get(int $index): mixed
public intersect(Ds\Set $set): Ds\Set
public isEmpty(): bool
public join(string $glue = ?): string
public last(): mixed
public merge(mixed $values): Ds\Set
public reduce(callable $callback, mixed $initial = ?): mixed
public remove(mixed ...$values): void
public reverse(): void
public reversed(): Ds\Set
public slice(int $index, int $length = ?): Ds\Set
public sort(callable $comparator = ?): void
public sorted(callable $comparator = ?): Ds\Set
public sum(): int|float
public toArray(): array
public union(Ds\Set $set): Ds\Set
public xor(Ds\Set $set): Ds\Set


Predefined Constants



Version Description
PECL ds 1.3.0 The class now implements ArrayAccess.

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