Question

我是JS的新手，我有点不确定我是否正确使用了switch语句或者是否有其他错误。我不断收到意外标识符错误。谁能告诉我这里有什么问题？非常感谢你提前。

function likes(names) {
    var outPut = "";

    switch(names){
        case (names.length === 1):
          outPut = names[0] = "likes this";
          break;
        case (names.length === 2):
          outPut = names[0] + "and" + names[1] + "like this";
          break;
        case (names.length === 3):
          outPut = names[0] + " , " + names[1] + " and " + names[2] + " like this";
          break;
        case (names.length >= 4):
          outPut = names[0] + names[1] + " and " names.length - 2 + "like this";
          break;
        default:
          outPut = "no one likes this";
    }
  return outPut;
}

Answer 1

names.length >= 4

中存在语法错误

最简洁的方法是if else阻止。

var output = "no one likes this";

if (names.length === 1) {
  outPut = names[0] = "likes this";
} else if (names.length === 2) {
  outPut = names[0] + "and" + names[1] + "like this";
} else(names.length === 3):
  outPut = names[0] + " , " + names[1] + " and " + names[2] + " like this";
} else if (names.length >= 4):
  outPut = names[0] + names[1] + " and " + (names.length - 2) + "like this";
}

如果您仍想使用switch，则可以稍微修改一下代码。

function likes(names) {
    var outPut = "";

    switch(names.length) {
        case 0:
            outPut = "no one likes this";
        case 1:
          outPut = names[0] = "likes this";
          break;
        case 2:
          outPut = names[0] + "and" + names[1] + "like this";
          break;
        case 3:
          outPut = names[0] + " , " + names[1] + " and " + names[2] + " like this";
          break;
        default:
          outPut = names[0] + names[1] + " and " +  (names.length - 2) + " like this";
    }
  return outPut;
}

Answer 2

这是使用switch：

执行此操作的正确方法

function likes(names) {
  var outPut = "";

  switch (names.length) {
    case 0:
      outPut = "no one likes this";
      break;
    case 1:
      outPut = names[0] + " likes this";
      break;
    case 2:
      outPut = names[0] + " and " + names[1] + " like this";
      break;
    case 3:
      outPut = names[0] + ", " + names[1] + " and " + names[2] + " like this";
      break;
    default:
      outPut = names[0] + ", " + names[1] + " and " + names[names.length - 2] + " like this";
      break;
  }
  return outPut;
}

console.log(likes(["Alice", "Bob", "Caesar"]));

但它不会显示更长阵列的所有名称。

Answer 3

outPut = names[0] + names[1] + " and " names.length - 2 + "like this";

看起来你忘了“和”和names.length之间的“+”。

outPut = names[0] = "likes this";

另外我认为第二个“=”应该是一个加号。

带有Switch语句的意外标识符

3 个答案: