Enum练习

1. 不带参数的Enum
创建Enum
public enum fruitEnum {
    APPLE,PEAR,BANANA,ORANGE;
}
测试Enum
public static void testFruitEnum(){

    for(fruitEnum fruit:fruitEnum.values()){
        System.out.println(fruit+",ordinal:"+fruit.ordinal()+",name:"+fruit.name());
    }
}
测试结果

APPLE,ordinal:0,name:APPLE
PEAR,ordinal:1,name:PEAR
BANANA,ordinal:2,name:BANANA
ORANGE,ordinal:3,name:ORANGE

Process finished with exit code 0

2. 带一个参数的Enum

创建Enum

public enum fruitEnum2 {
    APPLE("red"), BANANA("yellow"), ORANGE("orange"), PEAR("green");
    private final String color;
    fruitEnum2(String color) {
        this.color=color;
    }
    public String getColor(){
        return this.color;
    }
    public static fruitEnum2 getFruitByColor(String color){
        for(fruitEnum2 fruit:fruitEnum2.values()){
            if(fruit.getColor().equals(color)){
                return fruit;
            }
        }
        return null;
    }
    }

测试Enum

/*        test fruitEnum2
 */
public static void testFruitEnum2(){
    fruitEnum2 fruit = fruitEnum2.getFruitByColor("yellow");
    assert fruit != null;
    System.out.println(fruit+",color:"+fruit.getColor()+",ordinal:"+fruit.ordinal()+",name:"+fruit.name());
}
public static void main(String[] args){
    testFruitEnum2();
}

测试结果

BANANA,color:yellow,ordinal:1,name:BANANA

Process finished with exit code 0

3. 带两个参数的Enum

创建Enum

public enum fruitEnum3 {
    APPLE("red","happy"), BANANA("yellow","vitality"), ORANGE("orange","warm"), PEAR("green","calm");
    private String color;
    private String feeling;
    fruitEnum3(String color,String feeling) {
        this.color=color;
        this.feeling=feeling;
    }
    public String getColor(){
        return this.color;
    }
    public void setColor(String color){
        this.color=color;
    }
    public String getFeeling(){
        return this.feeling;
    }
    public void setFeeling(String feeling){
        this.feeling=feeling;
    }
        public static fruitEnum3 getFruitByColor(String color){
        for(fruitEnum3 fruit: fruitEnum3.values()){
            if(fruit.getColor().equals(color)){
                return fruit;
            }
        }
        return null;
    }
    public static fruitEnum3 getFruitByFeeling(String feeling){
        for(fruitEnum3 fruit: fruitEnum3.values()){
            if(fruit.getFeeling().equals(feeling)){
                return fruit;
            }
        }
        return null;
    }
    }

测试Enum

    /*        test fruitEnum3
     */
    public static void testFruitEnum3(){
//        fruitEnum3 fruit = fruitEnum3.getFruitByColor("yellow");
        fruitEnum3 fruit = fruitEnum3.getFruitByFeeling("warm");
        if (fruit != null) {
            System.out.println(fruit+",color:"+fruit.getColor()+",ordinal:"+fruit.ordinal()+",name:"+fruit.name());
        }
    }
    public static void main(String[] args){
        testFruitEnum3();
    }

测试结果

ORANGE,color:orange,ordinal:2,name:ORANGE

Process finished with exit code 0