切换语句

Question

如何在switch语句中添加条件？（例如：-显示平均分数的等级）

Answer 1

我建议使用if-else ... switch语句只能在相等时进行比较。

有了整数分数，您可以做类似...

switch (score)
{
  case 100:
  case 99:
  case 98:
  case 97:
  case 96:
  case 95:
  case 94:
  case 93:
  case 92:
  case 91:
  case 90:
    grade = 'A';
    break;
  case 89:
    /* ... */
}

看到问题了吗？ :-)

Answer 2

这是我在switch语句中使用小于大于的方法。 以下是动作脚本3 ...

var unknown1：Number = 8;

var unknown2：Number = 2;

var lowerBoundary = 1;

var upperBoundary = 5

开关（真）{

case (unknown2 < lowerBoundary || unknown2 > upperBoundary):
    trace("value is out of bounds");
break;

case (unknown2 > lowerBoundary && unknown2 < upperBoundary):
    trace("value is between bounds");
break;

default:
    trace("Out of Luck");
break;

}

输出...值在界限之间

Answer 3

你不能 使用if-else-if-else。

Answer 4

根据您的范围，可以使用公式。 例如

switch(score/10) {
  case 10: case 9: case 8: return 'A';
  case 7: return 'B';
  case 6: return 'C';
  case 5: return 'D';
  default: return 'U';
}

Answer 5

在此示例中，代码是否生成了一个随机数，如果是该数字或该数字，则执行某些操作。

int num;   //Just declares a variable 
Random r = new Random();   //This makes an object that generates random numbers.
num = r.nextInt(2);    //This "Choose" the random number. The possible numbers are 0 and 1. and the sets the the num variable to the number.  

switch(num){   

case 0:     //This says if the number is 0 then do this.
//put code here.
break;

case 1:    //This says if the number is 1 then do this.
//put code here
break;
}

这是一个switch语句，它根据随机选择的数目执行不同的操作。

Answer 6

该问题带有Java标记，因此...

通用switch语句：

// ... within class scope
private final int CONSTANT_1 = 1;
private final int CONSTANT_2 = 2;
private final int CONSTANT_3 = 3;
// ... 
public void doStuff(MyObject myObject){
   int variable = myObject.getIntValue();
   switch(variable){
   case CONSTANT_1:
      System.out.println(variable + " is equal to " + CONSTANT_1);
      // use a break statement to tell the switch to stop here
      // or else it will execute all subsequent cases:
      break;
   case CONSTANT_2: 
      System.out.println(variable + " is equal to " + CONSTANT_2);
      // what happens if I leave out the break?
   case CONSTANT_3:
      System.out.println(variable + " is equal to " + CONSTANT_2);
      break;
   default:
      System.out.println(variable + " wasn't equal to anything!");
}

假设我运行了3次，“ myObject.getIntValue（）”按此顺序返回这些值； 3、1、2，最后是42。然后将生成以下输出：第一次使用值'3'...

3等于3

第二次使用值“ 1” ...

1等于1

第三次使用值'2'...

2 is equal to 2
2 is equal to 3

第四次使用值'42'...

42不等于任何东西！

请注意，第三次运行有两行（其中一行是错误的），因为在第二种情况下，我省略了break关键字。

现在，在Java 1.5及更高版本中，您还可以打开Enum类型：

public void doStuff(MyObject myObject){
   MyEnumType varType = myObject.getEnum();
   switch(varType){
   case MyTypeOne:
   // everything else is the same -- nothing special here.
   // put whatever code you want in.
      break;
   case MyTypeTwo:
   // everything else is the same -- nothing special here.
   // put whatever code you want in.
      break;
   case MyTypeThree:
   // everything else is the same -- nothing special here.
   // put whatever code you want in.
      break;
   default:
        // code for unknown case goes here
   }
}