groupAnagrams.js

function groupAnnagrams(arr) {
    const arrObject = {} // create an empty object to store each words

    for(let i=0; i <arr.length; i++){
        arrObject[arr[i]] = {} // create empty object so it wont be undefined
        for(let j = 0; j < arr[i].length; j++){
            const key = arrObject[arr[i]][arr[i][j]];
            if(!key){ //check falsy value
                arrObject[arr[i]][arr[i][j]] = 1; // set 1 if not exist
            }else{
                arrObject[arr[i]][arr[i][j]] += 1; //increment if exist
            }
        }
    }

    let doneArr = []; // store all words that have been checked
    let result = [];
    for(let i = 0; i < arr.length; i++){
        let groups = [arr[i]]
        if(doneArr.includes(arr[i])) continue; // skip loop if string already checked
        for(let j = i+1; j < arr.length; j++){
            let count = 0;
            for(key in arrObject[arr[i]]){
            if(arrObject[arr[i]][key] === arrObject[arr[j]][key]){
                count++;
            }
            }
            if(count === Object.keys(arrObject[arr[i]]).length){ // check if all words are same
            groups.push(arr[j]);
            doneArr.push(arr[j]);
            }
        }
            result.push(groups)
    }
}

const input = ['kita','atik','tika','aku','kia','makan','kua'];
console.log(groupAnnagrams(input)); // [["kita", "atik", "tika"], ["aku", "kua"], ["kia"], ["makan"]]