phaser/examples/groups/get first.js

var game = new Phaser.Game(800, 600, Phaser.CANVAS, 'phaser-example', { preload: preload, create: create, update: update, render: render });

function preload() {

    game.load.spritesheet('item', 'assets/buttons/number-buttons-90x90.png', 90, 90);
    game.load.image('reviveBtn', 'assets/buttons/revive-button.png');
    
}

var timer;
var cycle;

function create() {

    // Add some items.
    var item;

    for (var i = 0; i < 3; i++)
    {
        // Give the items a different alpha increase speed.
        item = game.add.sprite(290, 98 * (i + 1), 'item', i);

        // An item beside the left one.
        item = game.add.sprite(388, 98 * (i + 1), 'item', i + 3);
    }

    // Set a timer so we can perform an action after a delay.
    timer = 0;
    cycle = 1000;
    
}

function update() {
    
    if (game.time.now > timer)
    {
        // Update timer.
        timer = game.time.now +cycle;
        
        // Get the first alive item and kill it.
        var item = game.world.getFirstAlive();

        if (item)
        {
            item.kill();
        }

    }

}

function render() {

    game.debug.renderText('One item will be killed each second.', 280, 420);

    // Get living and dead number of a group.
    game.debug.renderText('Living: ' + game.world.countLiving() + ', Dead: ' + game.world.countDead(), 330, 440);
    
}