Circular queue code implemented using arrays in javascript_javascript skills

//Circular Queue
function CircleQueue(size){
this.initQueue(size);
}
CircleQueue.prototype = {
//Initialization Queue
initQueue: function(size ){
this.size = size;
this.list = new Array();
this.capacity = size 1;
this.head = 0;
this.tail = 0 ;
},
//Push into queue
enterQueue: function(ele){
if(typeof ele == "undefined" || ele == ""){
return;
}
var pos = (this.tail 1) % this.capacity;
if(pos == this.head){//Determine whether the queue is full
return;
} else{
this.list[this.tail] = ele;
this.tail = pos;
}
},
//Get the head data from the queue
delQueue : function(){
if(this.tail == this.head){ // Determine whether the queue is empty
return;
}else{
var ele = this.list[this. head];
this.head = (this.head 1) % this.capacity;
return ele;
}
},
//Query whether this element exists in the queue, exists Return the subscript, if it does not exist, return -1
find : function(ele){
var pos = this.head;
while(pos != this.tail){
if(this.list [pos] == ele){
return pos;
}else{
pos = (pos 1) % this.capacity;
}
}
return -1;
},
//Return the number of elements in the queue
queueSize: function(){
return (this.tail - this.head this.capacity) % this.capacity;
} ,
//Clear the queue
clearQueue: function(){
this.head = 0;
this.tail = 0;
},
//Judge whether the queue is empty
isEmpty : function(){
if(this.head == this.tail){
return true;
}else{
return false;
}
}
}