simple circular queue

circular_queue.js

class CQ
{
    constructor(n)
    {
        this.arr=new Array(n)
        this.current=0
    }    

    add(data)
    {
        let index=(this.current+1)%this.arr.length
        this.arr[this.current]=data
        this.current=index
    }

    remove(data)
    {
        let index=this.arr.indexOf(data)
        if(index!=-1)
        {
            this.arr[index]=undefined
        }
            
    }

    take()
    {
        let data=this.arr[this.current]
        this.arr[this.current]=undefined
        this.current=(this.current+1)%this.arr.length
        return data
        
    }

    display()
    {
        console.log(this.arr)
    }
}

let cq=new CQ(10)

for(i=1;i<12;i++)
{
    cq.add(i)
    cq.display()
}

cq.remove(11)
cq.display()
cq.remove(10)
cq.display()

for(i=0;i<4;i++)
{
    console.log(cq.take())
    cq.display()
}