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/**
* Copyright (c) 2024 Araf Karsh Hamid
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
* or (per the licensee's choosing)
* under the terms of the Apache 2 License version 2.0
* as published by the Apache Software Foundation.
*/
package java21;
import static java.lang.System.out;
/**
* Java 14, 17 and 21 Example
* Switch Expression Example
*
* @author: Araf Karsh Hamid
* @version:
* @date:
*/
public class SwitchExpressionExample {
public static void main (String[] args) {
// Java 14
out.println("JAVA 14 >>>>>--------------------------------------------------------");
out.println("Simple Switch Expressions - No Fall Through");
out.println("< Day of the Week Old Model = "+switchOldModel(3));
out.println("> Day of the Week New Model = "+switchNewModel(3));
out.println("Complex Switch Expressions - No Fall Through");
out.println("< Day of the Week Old Model = "+switchOldModel(6));
out.println("> Day of the Week New Model = "+switchNewModel(6));
out.println("> Type of the Day. Monday = "+switchNewModel2("Monday"));
out.println("> Type of the Day. Sunday = "+switchNewModel2("Sunday"));
// Java 17
out.println("JAVA 17 >>>>>--------------------------------------------------------");
switchNewModel17(127);
switchNewModel17("127");
// Java 21
out.println("JAVA 21 >>>>>--------------------------------------------------------");
out.println("Condition: "+switchNewModel21(127));
out.println("Condition: "+switchNewModel21(90));
out.println("Condition: "+switchNewModel21("127"));
}
/**
* Old Model of Switch Statement
* @param day
* @return
*/
public static String switchOldModel(int day) {
String dayOfTheWeek = "Undefined";
switch(day) {
case 0: dayOfTheWeek = "Monday"; break;
case 1: dayOfTheWeek = "Tuesday"; break;
case 2: dayOfTheWeek = "Wednesday"; break;
case 3: dayOfTheWeek = "Thursday"; break;
case 4: dayOfTheWeek = "Friday"; break;
case 5: dayOfTheWeek = "Saturday"; break;
case 6:
System.out.println("Even God took Rest on Sunday!");
dayOfTheWeek = "Sunday";
break;
default: throw new RuntimeException("Illegal Day of the Week argument! >> "+day);
}
return dayOfTheWeek;
}
/**
* Switch Expressions
* No Fall Through like in the old model if breaks are missing.
* @param day
* @return
*/
public static String switchNewModel(int day) {
return switch(day) {
case 0 -> "Monday";
case 1 -> "Tuesday";
case 2 -> "Wednesday";
case 3 -> "Thursday";
case 4 -> "Friday";
case 5 -> "Saturday";
case 6 -> {
System.out.println("Even God took Rest on Sunday!");
yield "Sunday";
}
default -> throw new RuntimeException("Illegal Day of the Week argument! >> "+day);
};
}
public static String switchNewModel2(String day) {
// Using switch expression in Java 21
return switch (day.toUpperCase()) {
case "MONDAY", "TUESDAY", "WEDNESDAY", "THURSDAY", "FRIDAY" -> "Weekday";
case "SATURDAY", "SUNDAY" -> "Weekend";
default -> throw new IllegalArgumentException("Invalid day: " + day);
};
}
// Java 17 Feature
public static void switchNewModel17(Object o) {
switch (o) {
case Integer i -> out.println("Integer: "+ i);
case Long l -> out.println("Long: "+ l);
default -> out.println("Other: "+ o);
}
}
// Java 21 Feature
public static String switchNewModel21(Object o) {
return switch (o) {
case Integer i when i > 100 -> "Large integer";
case Integer i -> "Small integer";
case String s when s.length() > 5 -> "Long string";
case String s -> "Short string";
default -> "Unknown type";
};
}
}