javaScript Queue

function Queue() {

var items = [];

this.enqueue = function(element) {

items.push(element)

}

this.dequeue = function(element) {

items.shift()

}

this.front = function() {

return items[0]

}

this.isEmpty = function() {

return items.length == 0

}

this.size = function() {

return items.length

}

this.printf = function() {

console.log(items.toString())

}

this.print = function() {

console.log(items.toString())

}

}

var queue = new Queue();

console.log(queue.isEmpty());

queue.enqueue('shidengyun');

queue.enqueue('zhujing');

queue.print();

console.log(queue.size());

console.log(queue.isEmpty());

queue.dequeue();

queue.print();