const hash = {};

//  to get the value for a particular index
const get = index => typeof hash[index] !== "undefined" ? hash[index] : null;

//  add a new value in a particular index
const set = (index, data) => {
  if( typeof hash[index] === "undefined"){
    hash[index] = [];
  }
  hash[index].push(data);
}

//  remove a value from a particular index
const pop = (index, value) => {
  if( typeof hash[index] === "undefined"){
    return true;
  }
  
  const valueIndex = hash[index].indexOf(value);
  if(valueIndex > -1){
    hash[index].splice(valueIndex, 1);
  } 
  return true;
}

//  remove all values stored in a particular index
const remove = index => {
  if( typeof hash[index] !== "undefined"){
    delete hash[index];
  }
  return true;
}