collections

fn main() {
    let mut numbers = Vec::new();
    numbers.push(1);
    numbers.push(2);
    numbers.push(3);

<?php

use Illuminate\Support\Collection;

// Create collection
$posts = collect(Post::all());

use std::collections::HashSet;

fn main() {
    let mut words = HashSet::new();
    words.insert("hello");
    words.insert("world");

use std::collections::VecDeque;

fn main() {
    let mut queue = VecDeque::new();
    queue.push_back(1);
    queue.push_back(2);

use std::collections::HashMap;

fn main() {
    let mut scores = HashMap::new();
    scores.insert("Alice", 10);
    scores.insert("Bob", 20);

# Map - transform elements
[1, 2, 3, 4].map { |n| n * 2 }          # => [2, 4, 6, 8]
['alice', 'bob'].map(&:upcase)          # => ['ALICE', 'BOB']
users.map(&:email)                       # => ['alice@example.com', ...]

# Select/Reject - filter elements

package com.example.demo.examples;

import java.util.*;
import java.util.stream.Collectors;

public class StreamExamples {