返回句子中最大单词的长度

Question

我写了一个函数，它接收一个句子并计算该句子中最长的单词。

function findLongestWord(str) {
  var charArray = str.split(" ");
  var wordArray = [];

  for(var i = 0; i < charArray.length; i++ ) {
    wordArray.push(charArray[i].length);
    wordArray.sort();
    wordArray.reverse();
  }
  return wordArray[0];
}

我的函数可以处理如下输入:

findLongestWord("The quick brown fox jumped over the lazy dog");

但是当我通过它时:

findLongestWord("What if we try a super-long word such as otorhinolaryngology")

函数返回:

4

而不是

19

Answer 1

您的sort函数按词法对数组进行排序，因此您最终得到

[1,10,19,2,2,2,3,4,4,4]

反过来，得到

[4,4,4,3,2,2,2,19,10,1]

其中4是第一个数

你根本不需要排序，只用Math.max代替

function findLongestWord(str) {
    return Math.max.apply( null, str.split(" ").map( (x) => x.length) );
}

Answer 2

TL;DR

您的数字被排序为字符串。

要在函数中按降序将它们排序为数字，您应该这样做:

wordArray.sort(function(a, b) { return b - a; });

根据文档:

sort()方法对数组中的元素进行排序并返回数组。排序不一定是稳定的。默认排序

[…]

语法

arr.sort()

arr.sort(compareFunction)

参数

compareFunction可选

指定定义排序顺序的函数。如果省略，则根据每个字符的Unicode码位对数组进行排序

强调我的，所以你以这样的结尾:

var str = "What if we try a super-long word such as otorhinolaryngology";
var charArray = str.split(" ");
// now charArray == ["What", "if", "we", "try", "a", "super-long", "word", "such", "as", "otorhinolaryngology"]
// when you take the length of each word and end up with
var wordArray = [4, 2, 2, 3, 1, 10, 4, 4, 2, 19];
// and if you use plain wordArray.sort() without specific sort function you get
wordArray = [1, 10, 19, 2, 2, 2, 3, 4, 4, 4];
// and once reversed it is
wordArray = [4, 4, 4, 3, 2, 2, 2, 19, 10, 1];
// this is why you end up with wordArray[0] == 4

你也可以用一行代码实现整个函数:

function findLongestWord(str) {
  return str.split(/s+/).sort(function(a, b) { return b.length - a.length; })[0].length;
}
console.log("Longest word length = ", findLongestWord("The default sort order is according to string Unicode code points"));
console.log("Longest word length = ", findLongestWord("What if we try a super-long word such as otorhinolaryngology"));

Answer 3

与您的代码略有不同，但应该具有相同的结果!

function longestWord(string) {
    var str = string.split(" ");
    var longest = 0;
    for (var i = 0; i < str.length; i++) {
        if (longest < str[i].length) {
            longest = str[i].length;
        }
    }
    return longest;
}
console.log(longestWord("The quick brown fox jumped over the lazy dog"));
console.log(longestWord("What if we try a super-long word such as otorhinolaryngology"));

Answer 4

你可以得到一个单词长度的数组，然后使用Math.max.apply

function findLongestWord(str){
  return Math.max.apply(null, str.split(" ").map(x=>x.length));
}
var l = findLongestWord("What if we try a super-long word such as otorhinolaryngology")
console.log(l)

Answer 5

使用map和max来解决这个问题(在我看来):

function findLongestWord(str) {
    return Math.max.apply(null, str.split(" ").map(function(word){
        return word.length;
    }));
}

Answer 6

function findLongestWord(str) {
  return str.split(' ').reduce((m, w) => Math.max(m, w.length), 0);
}
var result = findLongestWord('The quick brown fox jumped over the lazy dog');
console.log(result);

Answer 7

最短路径:

console.log(
  'What if we try a super-long word such as otorhinolaryngology'
  .split(' ')
  .sort(function(a, b) {
    return b.length - a.length
  })[0].length
);

或作为函数:

function returnLongest(str) {
  return str
    .split(' ')
    .sort(function(a, b) {
      return b.length - a.length
    })[0].length;
}
console.log(returnLongest('What if we try a super-long word such as otorhinolaryngology'))

Answer 8

不必使用数组。如果您只想保存最长的单词，只需将最长长度与当前单词长度进行比较

function findLongestWord(str) {
  var charArray = str.split(" ");
  var longestWord = 0;
  for (var i = 0; i < charArray.length; i++) {
    let l = charArray[i].length;
    if (l > longestWord)
      longestWord = l;
  }
  return longestWord;
}
console.log(findLongestWord("The quick brown fox jumped over the lazy dog"));
console.log(findLongestWord("What if we try a super-long word such as otorhinolaryngology"));

Answer 9

sort函数将按字典顺序对数组进行排序，这不是您在这里想要的。如果希望对数字进行完美升序排序，还需要传递排序方法。此外，您在for循环中对数组进行排序和反转，因此每次添加项时都要执行此操作。

你应该做的是:

for(var i = 0; i < charArray.length; i++ ) {
    wordArray.push(charArray[i].length);
  }
wordArray.sort(ascendingSort);
wordArray.reverse();
function ascendingSort(a, b) {
    return a - b;
}
return wordArray[0];

Answer 10

你需要传递一个函数来排序:

function findLongestWord(str) {
  var charArray = str.split(" ");
  var wordArray = [];

  for(var i = 0; i < charArray.length; i++ ) {
    wordArray.push(charArray[i].length);
    wordArray.sort(function(a,b){
        return a > b;
    });
    wordArray.reverse();
  }
  return wordArray[0];
}
var longest = findLongestWord("What if we try a super-long word such as otorhinolaryngology");

Answer 11

请尝试下面的

 function findLongestWord(str) {
  var charArray = str.split(" ");
  var longestWordLength = 0;
  var longestWord = "";
  for(var i = 0; i < charArray.length; i++ ) {
    if(charArray[i].length > longestWordLength){
      longestWordLength = charArray[i].length;
      longestWord = charArray[i]
    }
  }
  return {longestWord , longestWordLength};
}