我不会使用switch语句来打印结果，但是如果您确实需要，我会创建两个函数，如下所示：

function getRank(strRank) {
  const rank = parseInt(strRank);
    if (rank >= 2400) return "Senior Master";
    if (rank >= 2200 && rank <= 2399) return "National Master";
    if (rank >= 2000 && rank <= 2199) return "Expert";
    if (rank >= 1800 && rank <= 1999) return "Class A";
    if (rank >= 1600 && rank <= 1799) return "Class B";
    else return "No rank";
} 

function printRank(rank) {
  switch (rank) {
    case "Senior Master":
    case "National Master":
    case "Expert":
    case "Class A":
    case "Class B":
      console.log(rank);
      break;
    default:
      console.log("No matching rank");
      break;
  }
}

printRank(getRank("2400")); // => "Senior Master"

您的代码中有一些错误。

1. 您不将console.log用于高级案卷

   case ("2400 + "):
     ("Senior Master"); // no console.log here.
     break;
   

2. 您不能在calculateRanking();内使用display()，因为calculateRanking()在display()的范围之外

3. 您想在calculateRanking()内传递排名，然后首先使其类似于calculateRanking(seniorMaster)，这将帮助您在calculateRanking(seniorMaster)

   中传递rank / score参数

4. 将display（）放入自执行函数中以允许其访问calculateRanking函数。

5. 最后，代码应该像

   (function (/*seniorMaster*/) { // you can remove the seniorMaster
   // parameter if it is not intended to use once. 
   
   function calculateRanking(seniorMaster) { //pass argument with it so 
   //that it could perform action according to input
       switch (seniorMaster) {
   
           //  if you don't want to use string comparsion but interested
          // to use numeric comparison then use
           case ("2400 + "): //  case (seniorMaster >= 2400):
   
               console.log("Senior Master");
   
               break;
   
           case ("2200 - 2399"):
   
               //  case (seniorMaster >= 2200 && seniorMaster < 2400):
   
               console.log("National Master");
   
               break;
   
           case ("2000 - 2199"): //  case (seniorMaster >= 2000 && seniorMaster < 2200):
   
               console.log("Expert");
   
               break;
   
           case ("1800 - 1999"): //  case (seniorMaster >= 1800 && seniorMaster < 2000):
   
               console.log("Class A");
   
               break;
   
           case ("1600 - 1799"): //  case (seniorMaster >= 1600 && seniorMaster < 1800):
   
               console.log("Class B");
       }
   }
   
   //calculateRanking(seniorMaster); --- You should be more specific to use it here as 
   // I don't think it would be useful to call it here if you want to
   // use display() to display ranking otherwise you are free to use it.
   
   //You don't require display() but still if there is 
   //some specific purpose of it you may use it
   
   function display(){
       //call the function here
       //here you
       var seniorMaster = "2400 + "; //  if you want to go with numeric comparison use --- 
       //var seniorMaster = Number_Value; (where Number_Value is any +Integer)
       calculateRanking(seniorMaster);
   }
   
   display();
   })();