Javascript：求解释

Question

这是完整的代码：

function LongestWord(sen) { 

  // we use the regex match function which searches the string for the
  // pattern and returns an array of strings it finds
  // in our case the pattern we define below returns words with
  // only the characters a through z and 0 through 9, stripping away punctuation
  // e.g. "hello$% ##all" becomes [hello, all]
  var arr = sen.match(/[a-z0-9]+/gi);

  // the array sort function takes a function as a parameter
  // which is used to compare each element in the array to the
  // next element in the array
  var sorted = arr.sort(function(a, b) {
    return b.length - a.length;
  });

  // this array now contains all the words in the original
  // string but in order from longest to shortest length
  // so we simply return the first element
  return sorted[0];

}LongestWord("the $$$longest# word is coderbyte"); 

但我只需要有人解释这部分：

var sorted = arr.sort(function(a, b) {
    return b.length - a.length;
  });

我确实了解函数和排序的工作原理，但它有点混杂，我的大脑崩溃了。 还有你能给我另一个简单的替代方案来解决这个问题>>最长的词，我用if-else和比较呢？

Answer 1

sort()函数可以参考documentation

更简单的替代方法见以下代码

function LongestWord(sen) {
  let longest = "";
  sen.match(/[a-z0-9]+/gi).forEach(function(word) {
    if (word.length > longest.length)
      longest = word;
  })
  return longest;
}
console.log(LongestWord("the $$$longest# word is coderbyte"));