### /com/in28minutes/java/enums/Enum.java
```
package com.in28minutes.java.enums;
//Enum can be declared outside a class
enum SeasonOutsideClass {
WINTER, SPRING, SUMMER, FALL
};
public class Enum {
// Enum can be declared inside a class
enum Season {
WINTER, SPRING, SUMMER, FALL
};
public static void main(String[] args) {
/*
* //Uncommenting gives compilation error //enum cannot be created in a
* method enum InsideMethodNotAllowed { WINTER, SPRING, SUMMER, FALL };
*/
// Converting String to Enum
Season season = Season.valueOf("FALL");
// Converting Enum to String
System.out.println(season.name());// FALL
// Default ordinals of enum
// By default java assigns ordinals in order
System.out.println(Season.WINTER.ordinal());// 0
System.out.println(Season.SPRING.ordinal());// 1
System.out.println(Season.SUMMER.ordinal());// 2
System.out.println(Season.FALL.ordinal());// 3
// Looping an enum => We use method values
for (Season season1 : Season.values()) {
System.out.println(season1.name());
// WINTER SPRING SUMMER FALL (separate lines)
}
// Comparing two Enums
Season season1 = Season.FALL;
Season season2 = Season.FALL;
System.out.println(season1 == season2);// true
System.out.println(season1.equals(season2));// true
}
}
```
### /com/in28minutes/java/enums/EnumAdvanced.java
```
package com.in28minutes.java.enums;
public class EnumAdvanced {
// Enum with a variable,method and constructor
enum SeasonCustomized {
WINTER(1), SPRING(2), SUMMER(3), FALL(4);
// variable
private int code;
// method
public int getCode() {
return code;
}
// Constructor-only private or (default)
// modifiers are allowed
SeasonCustomized(int code) {
this.code = code;
}
// Getting value of enum from code
public static SeasonCustomized valueOf(int code) {
for (SeasonCustomized season : SeasonCustomized.values()) {
if (season.getCode() == code)
return season;
}
throw new RuntimeException("value not found");// Just for kicks
}
// Using switch statement on an enum
public int getExpectedMaxTemperature() {
switch (this) {
case WINTER:
return 5;
case SPRING:
case FALL:
return 10;
case SUMMER:
return 20;
}
return -1;// Dummy since Java does not recognize this is possible :)
}
};
public static void main(String[] args) {
SeasonCustomized season = SeasonCustomized.WINTER;
/*
* //Enum constructor cannot be invoked directly //Below line would
* cause COMPILER ERROR SeasonCustomized season2 = new
* SeasonCustomized(1);
*/
System.out.println(season.getCode());// 1
System.out.println(season.getExpectedMaxTemperature());// 5
System.out.println(SeasonCustomized.valueOf(4));// FALL
}
}
```
### /com/in28minutes/java/enums/EnumAdvanced2.java
```
package com.in28minutes.java.enums;
public class EnumAdvanced2 {
// Enum with a variable,method and constructor
enum SeasonCustomized {
WINTER(1) {
public int getExpectedMaxTemperature() {
return 5;
}
},
SPRING(2), SUMMER(3) {
public int getExpectedMaxTemperature() {
return 20;
}
},
FALL(4);
// variable
private int code;
// method
public int getCode() {
return code;
}
// Constructor-only private or (default)
// modifiers are allowed
SeasonCustomized(int code) {
this.code = code;
}
public int getExpectedMaxTemperature() {
return 10;
}
};
public static void main(String[] args) {
SeasonCustomized season = SeasonCustomized.WINTER;
System.out.println(season.getExpectedMaxTemperature());// 5
System.out.println(SeasonCustomized.FALL.getExpectedMaxTemperature());// 10
}
}
```