如果存在於 JS 中，則連接不同的變量

Question

我想連接不同的變量（如果存在）並返回結果。 但是我需要用“-”分隔值，只返回有值的變量。

所以我有這個：

  var test = "";
  var test1 = "";
  var test2 = "";
  var test3 = "";

  var checkTrue = "Rightt";
  var checkFalse = "Wrong";
  var checkWord = "Helloo";
  var checkWord2 = "Bye";

  if(checkTrue === "Right"){
    test = "This is right"
  } else {
    test = "";
  }

  if(checkFalse === "Wrong"){
    test1 = "This is wrong"
  } else {
    test1 = "";
  }

  if(checkWord === "Hello"){
    test2 = "The word is hello"
  } else {
    test2 = "";
  }

  if(checkWord2 === "Bye"){
    test3 = "The word is hello"
  } else {
    test3 = "";
  }

  var result = test + " - " + test1 + " - " + test2 + " -" + test3;
  console.log(result);

所以我想我需要在我的 var 結果之前驗證是否存在不同的變量？

感謝您的幫助

實際結果：

 - This is wrong -  -The word is hello

預期結果：

This is wrong - The word is hello

Answer 1

對於任何你想要在字符串值之間使用分隔符的東西，我發現使用Array.prototype.join()會更容易，它只會在實際值之間放置分隔符。

然后它變得更容易，因為你有一個可以連接的results數組，只添加你想要的值而不是測試你不再需要的每個變量。

通過推送到一個數組，您也可以擺脫所有這些test變量。

 const results = []; const checkTrue = "Rightt"; const checkFalse = "Wrong"; const checkWord = "Helloo"; const checkWord2 = "Bye"; if (checkTrue === "Right") results.push("This is right") if (checkFalse === "Wrong") results.push("This is wrong") if (checkWord === "Hello") results.push("The word is hello") if (checkWord2 === "Bye") results.push("The word is hello") const result = results.join(" - "); console.log(result);

Answer 2

 const test = ''; const test1 = 'This is wrong'; const test2 = ''; const test3 = 'The word is hello' const result = [test, test1, test2, test3].filter(value => value).join(' - '); console.log(result);