Find all the words in a string which have the greatest length

问题

I want to find all the words from the string which have the greatest length.

At the moment, the result is just the first with the greatest length: 'jumped1', whereas I want them all: ['jumped1', 'jumped2'].

How can I adapt the following?

function test(str) {

  var newStr = str.split(' ');
  var nu = 0;
  var word =null;

  for(var i=0; i < newStr.length; i++){
     if(newStr[i].length > nu){
       nu = newStr[i].length; // length
       word = newStr[i]; // word

     }    
  }
  return word;
}

console.log(test("The quick brown fox jumped1 over the lazy dog - jumped2"));

回答1:

Instead of assigning to a variable, word, when you find longest word, push it to an array of longest words. You have to handle blanking the array though when a new longest word is found.

function test(str) {
  var split_string = str.split(' ');
  var longest_length = 0;
  var words = [];
  for(let string of split_string){
     if(string.length > longest_length){
       words = [string];
       longest_length = string.length;
     } else if (string.length == longest_length){
       words.push(string);
     }
  }
  return words;
}

console.log(test("The quick brown fox jumped1 over the lazy dog - jumped2"));

回答2:

You can use reduce to get the length of the longest word and then filter to get the list of words of that length:

function test(str) {
  var words = str.split(' ');
  var maxLen = words.reduce(function(num, word){
    return Math.max(num, word.length);
  }, 0);
  
  return words.filter(function(word){
    return word.length == maxLen
  });
}

console.log(test("The quick brown fox jumped1 over the lazy dog - jumped2"));

回答3:

If I understand the question correctly, you can use filter after finding the max length in order to return an Array of every word with length === max

function test (str) {
  let words = str.split(' ')
  let max = 0
  words.forEach(word => {
    if (word.length > max) max = word.length
  })
  return words.filter(word => word.length === max)
}

console.log(
test("The quick brown fox jumped1 over the lazy dog - jumped2")
)

回答4:

You could reduce the array by collecting longer words or with same length.

function test(string) {
    return string
        .split(' ')
        .reduce((r, w) => {
            if (!r || r[0].length < w.length) {
                return [w];
            }
            if (r[0].length === w.length) {
                r.push(w);
            }
            return r;
        }, undefined);
}

console.log(test("The quick brown fox jumped1 over the lazy dog - jumped2"));

来源：https://stackoverflow.com/questions/52130686/find-all-the-words-in-a-string-which-have-the-greatest-length

标签

javascript

ecmascript-6