Java8 Programming Examples

Compile and Execute Java8 Online

java8

public class ArithmeticOperatorDemo {
    public static void main(String args[]){
        int num1 = 100;
        int num2 = 25;
        System.out.println("num1 + num2 : " + (num1+num2));
        System.out.println("num1 - num2 : " + (num1-num2));
        System.out.println("num1 * num2 : " + (num1*num2));
        System.out.println("num1 / num2 : " + (num1/num2));
        System.out.println("num1 % num2 : " + (num1%num2));
    }
}

saia

java8

import java.util.*;
public class HelloWorld{

     public static void main(String []args){
     
         Scanner sc=new Scanner(System.in);
         String s="";
         s=sc.nextLine();
     }
}

Roman to Int

java8

public class HelloWorld{

     public static void main(String []args){
        // System.out.println(romanToInt("I"));
        // System.out.println(romanToInt("II"));
        // System.out.println(romanToInt("III"));
        // System.out.println(romanToInt("IV"));
        // System.out.println(romanToInt("V"));
        // System.out.println(romanToInt("VI"));
        // System.out.println(romanToInt("VIII"));
        System.out.println(romanToInt("CIX"));
        // System.out.println(romanToInt("X"));
        // System.out.println(romanToInt("XI"));
        // System.out.println(romanToInt("XII"));
        // System.out.println(romanToInt("XII"));
        // System.out.println(romanToInt("XIV"));
        // System.out.println(romanToInt("XV"));
     }
     
    static int romanToInt(String s) {
        int nums[]=new int[s.length()];
        for(int i=0;i<s.length();i++){
            switch (s.charAt(i)){
                case 'M':
                    nums[i]=1000;
                    break;
                case 'D':
                    nums[i]=500;
                    break;
                case 'C':
                    nums[i]=100;
                    break;
                case 'L':
                    nums[i]=50;
                    break;
                case 'X' :
                    nums[i]=10;
                    break;
                case 'V':
                    nums[i]=5;
                    break;
                case 'I':
                    nums[i]=1;
                    break;
            }
        }
        int sum = 0;
        for(int i = 0; i < nums.length - 1; i++) {
            if(nums[i] < nums[i+1]) {
                sum -= nums[i];
            }
            else {
                sum += nums[i];
            }
            System.out.println(nums[i] + ", " + sum);
        }
        System.out.println(sum + ", " + nums[nums.length - 1]);
        return sum + nums[nums.length - 1];
    }
}

17220018 Heni listiani

java8

public class belajar03{

     public static void main(String []args){
        System.out.println("belajar03");
        int panjang, lebar, luas, keliling;
        panjang = 10;
        lebar = 15;
        luas = panjang * lebar;
        System.out.println("Luas persegi panjang = " + luas);
        keliling = 2 * (panjang * lebar);
        System.out.println("keliling persegi panjang = " + keliling);
     }
}

17220018 Heni Listiani

java8

public class Belajar01{

     public static void main(String []args){
        System.out.println("Belajar01");
        System.out.println("Nama : Heni Listiani");
        System.out.println("NIM : 17220018");
     }
}

Reverse Integer

java8

public class HelloWorld{

    public static void main(String []args){
        System.out.println("Max " + Integer.MAX_VALUE);
        System.out.println("Min " + Integer.MIN_VALUE);
        System.out.println("Reverse " + reverse1(1000000007));
        System.out.println("Reverse " + reverse1(-1234567890));
    }
    
    static int reverse2(int x) {
        long rev= 0;
        while( x != 0){
            rev= rev*10 + x % 10;
            x= x/10;
            if( rev > Integer.MAX_VALUE || rev < Integer.MIN_VALUE)
                return 0;
        }
        return (int) rev;
    }
    static int reverse1(int num) {
        long result = 0;
        
        while(num != 0) {
            // int temp = num % 10;
            result = (result * 10) + (num % 10);
            // System.out.println(result);
            // System.out.println((newResult - temp) /10);
            // if((newResult - temp) /10 != result) {
            if( result > Integer.MAX_VALUE || result < Integer.MIN_VALUE) {
                return 0;
            }

            // result = newResult;
            num = num / 10;
        }
        return (int)result;
    }
    
    

    
}

Two Sum

java8

import java.util.HashMap;
import java.util.Map;

public class HelloWorld{

    public static void main(String []args){
        int[] nums = {4,2,6,10,5,3};
        
        int target = 2;
        int[] result = twoSum(nums, target);
        System.out.println(result[0] + " + " + result[1] + " = " + target);
    }
    
    static int[] twoSum(int[] nums, int target) {
        HashMap<Integer,Integer> map = new HashMap();
        
        for(int i = 0; i < nums.length; i++) {
            int compliment = target - nums[i];
            // System.out.println("num "+ nums[i] + ", " + compliment);
            Integer found = map.get(compliment);
            // System.out.println("   found "+ found);
            // if(found != null) {
            //                 System.out.println("   value "+ map.get(compliment));
            // }
            if(map.get(compliment) != null) {
                return new int[]{nums[map.get(compliment)], nums[i]};
            }
            map.put(nums[i], i);
            // printKeys(map);
            
        }
        throw new Error("No sum found.");
    }
    
    static void printKeys(Map<Integer, Integer> map) {
        for(Integer key : map.keySet()) {
            System.out.println("  key " + key);
        }
    }
}

Exceptions-2

java8

public class HelloWorld{

     public static void main(String []args){
        System.out.println("Hello World");
     }
}

Exceptions-1

java8

public class HelloWorld
{
     public static void main(String []args)
     {
        String myMessage = null;

        try
        {
            myMethod(myMessage);
        }
        catch (NullPointerException e)
        {
            System.out.println("Caught a null pointer exception!");
        }
        catch (Exception e)
        {
            System.out.println("Caught an exception: " + e.getClass() + ": " + e.getMessage());        
        }
        finally
        {
            System.out.println("finally block always executed");
        }
    
        System.out.println("Hello World");
     }
     
     public static void myMethod(String s)
     {
         System.out.println(s.length());
     }
}

Enums

java8

public class HelloWorld
{
     enum DayOfWeek
     {
         SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY;
     }
     
     enum DayOfWeekExtended
     {
         SUNDAY(0), MONDAY(1), TUESDAY(3), WEDNESDAY(4), THURSDAY(5), FRIDAY(6), SATURDAY(7);
         
         public final int dayNumber;
         
         DayOfWeekExtended(int day)
         {
             dayNumber = day;
         }
         
         public int getDayNumber() { return dayNumber; }
     }
     
     public static void main(String []args)
     {
        DayOfWeek day = DayOfWeek.TUESDAY;
        
        System.out.println("day value is " + day + " and I can do this " + DayOfWeek.TUESDAY);
        
        switch (day)
        {
            case MONDAY:
                System.out.println("day = Monday");
                break;
                
            case TUESDAY:
                System.out.println("day = Tuesday");
                break;
                
            case WEDNESDAY:
                System.out.println("day = Wednesday");
                break;
                        
        }

        DayOfWeekExtended dayx = DayOfWeekExtended.TUESDAY;
        
        System.out.println("\ndayx value is " + dayx + " and I can do this " + DayOfWeekExtended.TUESDAY);
        
        switch (dayx)
        {
            case MONDAY:
                System.out.println("dayx = Monday");
                break;
                
            case TUESDAY:
                System.out.println("dayx = Tuesday");
                break;
                
            case WEDNESDAY:
                System.out.println("dayx = Wednesday");
                break;
                        
        }
        
        System.out.println("The dayx number is " + dayx.dayNumber + " and " + dayx.getDayNumber());
   }
}

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