Time complexity of includes() function in JavaScript

Question

I have an array that contains some hash values of certain strings, I don\'t want duplicate values in my array so I use if logic like this

if(!a         


        

Answer 1

as my list is not sorted so i have create a dictionary and put values into it after checking if value present in it or not . Here in this dictionary my value and key are same .

var   arrayOfHashMap = {};/*is a dictionary,arrayOfValue is a list*/
    if(arrayOfHashMap[hash_value] !=hash_value){
                               arrayOfValue.push(hash_value); 
                               arrayOfHashMap[hash_value]=hash_value;
                        }

in this case I search values in o(1) time and put them in arrayOfValue