switch case

官方文档

switch - JavaScript | MDN

梗概

• 类似于bat goto语句语句，当指定条件===case值时，将会跳转到对应case，直到遇到break

• switch符合多个case则只会跳转第一个符合的case

实例

单case单操作

switch (expr) {
  case "Oranges":
    console.log("Oranges are $0.59 a pound.");
    break;
  case "Apples":
    console.log("Apples are $0.32 a pound.");
    break;
  case "Bananas":
    console.log("Bananas are $0.48 a pound.");
    break;
  case "Cherries":
    console.log("Cherries are $3.00 a pound.");
    break;
  case "Mangoes":
  case "Papayas":
    console.log("Mangoes and papayas are $2.79 a pound.");
    break;
  default:
    console.log("Sorry, we are out of " + expr + ".");
}
console.log("Is there anything else you'd like?");
 

多case单操作

var Animal = "Giraffe";
switch (Animal) {
  case "Cow":
  case "Giraffe":
  case "Dog":
  case "Pig":
    console.log("This animal will go on Noah's Ark.");
    break;
  case "Dinosaur":
  default:
    console.log("This animal will not.");
}