Question

作为我学习练习的一部分，我正在尝试使用For循环创建一个函数。该函数返回一个新的数组变量merges并匹配数组Y = eye(num_labels)(y, :);和musicians的索引值。所以预期的回报应该是字符串： “约翰·列侬演奏吉他”

这是我的尝试，但我一直没有得到回报：

instruments

Answer 1

您在循环的每次迭代中都会覆盖变量。您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));

Answer 2

存在一些问题。

该函数需要返回合并的数组。其次，函数从未被调用过。您可能不需要再次在循环中创建变量

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))

Answer 3

根据您的代码进行的观察很少：

在for循环中的每个语句后添加 ; ，以获得良好的编码实践。
将console.log语句放在for循环中，因为它会在for循环中打印迭代值。
而不是newMusicians[i]在console.log中使用newMusicians。

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);

Answer 4

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

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);

javascript for循环函数合并两个新数组。

4 个答案: