LeetCode 49. Group Anagrams

/**
 * @param {string[]} strs
 * @return {string[][]}
 */
var groupAnagrams = function(strs) {
    const map = []
    
    for (let i = 0; i<strs.length; i++) {
        const str = strs[i].split('').sort().join('')
        if (!map[str]) map[str] = []
        map[str].push(strs[i])
    }
    const ans = []
    for (let k in map) {
        ans.push(map[k])
    }
    return ans
};