找到字符串任务中最长的单词时出错(javascript)

Question

我正在使用freecodecamp.com,任务是查找字符串中最长的单词,我收到此错误,我无法理解为什么我也查看了其他项目.

"TypeError:无法获取未定义或空引用的属性'长度'"

它指的是 copy[i].length

function findLongestWord(str) {
  var copy = str;
  copy = copy.split(' ');
  var longest = 0;
  for (var i = 0;i < copy.length;i++);
  {
    if (longest < copy[i].length)
      {
        longest = copy[i].length;
      }
  }
  return longest;
}
findLongestWord("The quick brown fox jumped over the lazy dog");

Answer 1

你的for循环之后你有一个半冒号.

function findLongestWord(str) {
  var copy = str;
  copy = copy.split(' ');
  var longest = 0;
  for (var i = 0;i < copy.length;i++)
  {
    if (longest < copy[i].length)
      {
        longest = copy[i].length;
      }
  }
  return longest;
}
var l = findLongestWord("The quick brown fox jumped over the lazy dog");
console.log('Longest = ' + l);