使用Javascript中的Map从一组字谜中查找唯一的单词

Question

I know how to do it without Map . It seems more logical to use Map for this task but I can't seem to implement it. Is this even possible?

So far I tied this:

function aclean(arr) {
  let result = [];
  let unique = new Map();

  for(let i = 0; i < arr.length; i++){
    let sorted = arr[i].toLowerCase().split("").sort().join("");

    /*if (unique.add(sorted)) {
      result.push(arr[i]);
    }*/
  }

  return result;
}

let array = ["nap", "teachers", "cheaters", "PAN", "ear", "era", "hectares"];

console.log(aclean(array));

The result should be: nap,teachers,ear or PAN,cheaters,era

Answer 1

You could take a Set with the normalized (lower case, sorted) strings and return a filtered result.

 function aclean(array) { let unique = new Set(); return array.filter(s => { let sorted = s.toLowerCase().split("").sort().join(""); if (!unique.has(sorted)) { unique.add(sorted); return true; } }); } let array = ["nap", "teachers", "cheaters", "PAN", "ear", "era", "hectares"]; console.log(aclean(array)); 

Answer 2

You could loop over your array using .forEach() , and check at each iteration whether or not your Map has a key of the sorted word, if it doesn't, then you set the sorted word as the key, and the word associated with the word as the value. You can then return an array of your map's .values() to get your result:

 function aclean(arr) { let unique = new Map(); arr.forEach(word => { let sorted = word.toLowerCase().split("").sort().join(""); if(!unique.has(sorted)) { unique.set(sorted, word); } }); return [...unique.values()]; } let array = ["nap", "teachers", "cheaters", "PAN", "ear", "era", "hectares"]; console.log(aclean(array)); 

Answer 3

I think Set is prefect for this case. You can do it in following steps.

• First make a helper function which sorts to the strings.
• Then create a unique array of sorted strings using Set and map()
• Then map() that array again to the value in original array which is anagram of the sorted string.

 const sort = str => str.toLowerCase().split('').sort().join('') const aclean = arr => [... new Set(arr.map(sort))].map(x => arr.find(a => sort(a) === x)) let array = ["nap", "teachers", "cheaters", "PAN", "ear", "era", "hectares"]; console.log(aclean(array));