不懂概念答案

【问题标题】：Don't Understand Concept不懂概念
【发布时间】：2021-08-31 22:21:51
【问题描述】：

给定下面的数组，创建一个循环遍历每个名称的函数，比较每个的长度确定最长的名称，将该名称保存到变量中最长的名字。将最长名称返回到另一个名为 answer 的变量并记录向屏幕回答变量。

let array = [ "John", "Lee", "Smitty", "Cyren", "Linda", "Bart", "Jason", "Wilson", "Travis", "Newt"];

会不会是这样的

let array = [ "John", "Lee", "Smitty", "Cyren", "Linda", "Bart", "Jason", "Wilson", "Travis", "Newt"];

let result = array.filter(val =>includes(val));

console.log(result);

【问题讨论】：

标签： javascript arrays function compare string-length

【解决方案1】：

只需对数组使用reduce，每次都返回最长的元素。

longest 变量将包含最后一个最长的元素。

运行 sn-p 并了解 reduce、? : (Elvis operator) 在 javascript 中的工作原理

let array = [ "John", "Lee", "Smitty", "Cyren", "Linda", "Bart", "Jason", "Wilson", "Travis", "Newt"];
let longest = array.reduce((prev, curr) => curr.length > prev.length ? curr : prev,'');
console.log(longest)

希望这有帮助?

【讨论】：

【解决方案2】：

这是一个示例实现。

// A function which accepts an array as input
function findLongest(names) {
  let longest_name = '';
  // Loop through all the names
  for (let i = 0; i < names.length; i += 1) {
    // If the names is longer than longest_name, update it
    if (names[i].length > longest_name.length) {
      longest_name = names[i];
    }
  }
  return longest_name;
}

let array = [ "John", "Lee", "Smitty", "Cyren", "Linda", "Bart", "Jason", "Wilson", "Travis", "Newt"];

let answer = findLongest(array);

console.log(answer)

【讨论】：

非常感谢。我真的很感激。