用于合并两个新数组的 javascript for 循环函数。答案

【问题标题】：javascript for loop function to merge two new arrays.用于合并两个新数组的 javascript for 循环函数。
【发布时间】：2017-05-25 20:37:31
【问题描述】：

作为学习练习的一部分，我正在尝试创建一个带有 For 循环的函数。该函数返回一个新的数组变量合并并匹配数组musicians 和instruments 的索引值。所以预期的回报应该是字符串： “约翰列侬弹吉他”

这是我的尝试，但我一直没有得到回报：

var musicians = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Starr"]
var instruments = ["Guitar", "Bass Guitar", "Lead Guitar", "Drums"]

  function theBeatlesPlay(musicians, instruments) {      

    for (let i=0; i<musicians.length; i++) {

      var newMusicians = musicians[i]
      var newInstruments = instruments[i]
    }

    console.log(newMusicians[i] + "plays" + instruments[i])
  }

【问题讨论】：

console.log 应该在 for 循环内
将 console.log 放在 for 循环中。此外，不需要这些变量。

标签： javascript arrays for-loop

【解决方案1】：

您在循环的每次迭代中都会覆盖您的变量。你需要创建一个空数组并填充它（然后返回它）：

var musicians = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Starr"]
var instruments = ["Guitar", "Bass Guitar", "Lead Guitar", "Drums"]

function theBeatlesPlay(musicians, instruments) {
  var combinations = [];

  for (let i = 0; i < musicians.length; i++) {
    combinations.push(musicians[i] + ' plays ' + instruments[i]);
  }

  return combinations;
}

console.log(theBeatlesPlay(musicians, instruments));

【讨论】：

【解决方案2】：

有几个问题。

函数需要返回合并后的数组。其次，该函数从未被调用。您可能不需要在循环内再次创建变量

var musicians = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Starr"]
var instruments = ["Guitar", "Bass Guitar", "Lead Guitar", "Drums"]


function theBeatlesPlay(musicians, instruments) {
  var mergedArray = [];

  for (let i = 0; i < musicians.length; i++) {
    mergedArray.push(musicians[i] + " plays " + instruments[i])

  }
  return mergedArray;

}
console.log(theBeatlesPlay(musicians, instruments))

【讨论】：

【解决方案3】：

根据您的代码很少观察到：

在 for 循环内的每个语句之后添加 ;，以获得良好的编码习惯。
将console.log 语句放入for 循环中，因为它将打印在for 循环中迭代的值。
在 console.log 中使用 newMusicians 而不是 newMusicians[i]。

var musicians = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Starr"]
var instruments = ["Guitar", "Bass Guitar", "Lead Guitar", "Drums"]

  function theBeatlesPlay(musicians, instruments) {      

    for (let i = 0; i < musicians.length; i++) {
      var newMusicians = musicians[i];
      var newInstruments = instruments[i];
      console.log(newMusicians + " plays " + instruments[i]);
    }
  }
  
 theBeatlesPlay(musicians, instruments);

【讨论】：

【解决方案4】：

您需要将console.log 放入for 循环中。
另外，console.log(newMusicians + " plays " + instruments[i])

newMusicians 而不是newMusicians[i] 登录时

var musicians = ["John Lennon", "Paul McCartney", "George Harrison", "Ringo Starr"]
var instruments = ["Guitar", "Bass Guitar", "Lead Guitar", "Drums"]

  function theBeatlesPlay(musicians, instruments) {      

    for (let i=0; i<musicians.length; i++) {

      var newMusicians = musicians[i];
      var newInstruments = instruments[i];
      console.log(newMusicians + " plays " + instruments[i])
    }

    
  }
  
  theBeatlesPlay(musicians, instruments);

【讨论】：