Put all words that match a criterion to a Map-CodePudding

I'm really new at JavaScript and I faced the first issue that I'm trying to solve.

The goal of a program is to use first letter of each word as a key and the unique words as a values.

Here is the code:

function sortToMap(str){
    let lowerString = str.toLowerCase();
    let result = lowerString.split(" ");
    let myMap = new Map();

    for(let i = 0; i < result.length; i  ){
        myMap.set(result[i][0], result[i]);
    }
    return myMap;
}

let myString = "Test string to check How it Works and hopefully it is fine";
console.log(sortToMap(myString));

So it looks like this:

(Actual result)

Map(8) {
  't' => 'to',
  's' => 'string',
  'c' => 'check',
  'h' => 'hopefully',
  'i' => 'is',
  'w' => 'works',
  'a' => 'and',
  'f' => 'fine'
}

(Expected result)

Map(8) {
  't' => 'test', 'to',
  's' => 'string',
  'c' => 'check',
  'h' => 'hopefully',
  'i' => 'it', 'is',
  'w' => 'works',
  'a' => 'and',
  'f' => 'fine'
}

I'm trying to figure out what can I do to achieve the expected result. Are there any suggestions?

CodePudding user response：

The value should be an array of words. Check if the map entry exists. If it does, push onto it, otherwise create it.

function sortToMap(str) {
  let lowerString = str.toLowerCase();
  let result = lowerString.split(" ");
  let myMap = new Map();

  for (let i = 0; i < result.length; i  ) {
    let initial = result[i][0];
    if (myMap.has(initial)) {
      if (!myMap.get(initial).includes(result[i])) {
        myMap.get(initial).push(result[i]);
      }
    } else {
      myMap.set(initial, [result[i]]);
    }
  }
  return myMap;
}

let myString = "Test string to check How it Works and hopefully it is fine";
console.log(Object.fromEntries(sortToMap(myString)));

CodePudding user response：

Instead of setting the word as the value, you should create an array that stores all the words starting with a given letter.

Here is a working code :

function sortToMap(str) {
   const words = str.toLowerCase().split(" ")
   // no need for map in JS, an object will work fine
   const map = {}
   for(let word of words) {
      const key = word[0]
      if(!(key in map))
         map[key] = []
      map[key].push(word)
   }
   
   return map
}

let myString = "Test string to check How it Works and hopefully it is fine";
console.log(sortToMap(myString));