var CQueue = function() {    
    this.inStack = [];
    this.outStack = [];
};
CQueue.prototype.appendTail = function(value) {    
    this.inStack.push(value);
};

​CQueue.prototype.deleteHead = function() {    
    if (!this.outStack.length) {        
        while (this.inStack.length) {            
            this.outStack.push(this.inStack.pop());
        }
    }    
    if (this.outStack.length) {        
        return this.outStack.pop();
    } else {        
        return -1;
    }
};

老师，请教下这样实现是不是更简单一点，判断输出的栈里为空的时候再将输入栈的数据压进去，省去每次都要压栈、出栈的操作