Create a Hash Table Challenge - Help

JavaScript
#1

Tell us what’s happening:
I can’t pass the test regarding collisions. Even though I’ve checked in the console and the program takes into account collisions and works fine, when i run the tests it just fails.
Does anyone have any idea what I’m doing wrong?

Your code so far


var called = 0;
var hash = string => {
called++;
var hashed = 0;
for (var i = 0; i < string.length; i++) {
  hashed += string.charCodeAt(i);
}
return hashed;
};

var HashTable = function() {
this.collection = {};

this.add = function(key, value) {
  var hashed = hash(key);
  if (!this.collection.hasOwnProperty(hashed)) {
    this.collection[hashed] = [];
    this.collection[hashed].push([key, value]);
  } else {
    var match = false;
    for (var i = 0; i < this.collection[hashed].length; i++) {
      if (this.collection[hashed][i][0] == key) {
        this.collection[hashed][i][1] = value;
        match = true;
      }
    }
    if (!match) {
      this.collection[hashed].push([key, value]);
    }
  }
};

this.remove = function(key) {
  var hashed = hash(key);
  for (var j = 0; j < this.collection[hashed].length; j++) {
    if (this.collection[hashed][j][0] == key) {
      var deleted = this.collection[hashed].splice(j, 1);
    }
  }
};

this.lookup = function(key) {
  var hashed = hash(key);
  for (let elem in this.collection[hashed]) {
    if (this.collection[hashed][elem][0] == key) {
      return this.collection[hashed][elem][1];
    }
    return null;
  }
};
}

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36.

Challenge: Create a Hash Table

Link to the challenge:
https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/create-a-hash-table

#2

the problem is in your this .lookup method .
You need to check for if(this.collection.hasOwnProperty(hashed)){} .if conditions is true then return the value ,else return null

#3