Posts Tagged ‘Java Tutorials for Beginners’
Using For Each in Java
Posted April 2, 2020
on:- In: Core Java Tutorials | Java Source Code | Java Tutorials
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Objective:
- How to use For Each in Java?
- How to use advance for in Java?
- How to use advance for loop in Java Programming Language?
- Types of For loop in Java
Source Code:
class ForEachExample { public static void main(String args[]) { //declaring an array int a[]={1,2,3,4,5,6}; // Old way System.out.println("Old way"); for(int i=0; i<a.length;i++) { System.out.println(a[i]); } //New way: for-each loop System.out.println("For each"); for(int i:a) { System.out.println(i); } } }
- In: Core Java Tutorials | How to's | Java Source Code | Java Tutorials
- Comments Off on Pattern Programs in Java – Pattern 2
Pattern 2 :
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
Java Program for the above pattern:
import java.util.Scanner; public class MainClass { public static void main(String[] args) { Scanner sc = new Scanner(System.in); //Taking rows value from the user System.out.println("How many rows you want in this pattern?"); int rows = sc.nextInt(); System.out.println("Here is your pattern....!!!"); for (int i = 1; i <= rows; i++) { for (int j = 1; j <= i; j++) { System.out.print(i+" "); } System.out.println(); } //Close the resources sc.close(); } }
Objectives :
- Convert Decimal number to Roman number
- Convert Decimal numeral to Roman numeral
- How to convert a decimal number to roman number
- Write a program that converts a decimal number to Roman number.
- Write a program that converts a decimal number to Roman number. Decimal Number is accepted using Scanner class at the time of execution.
- Write a program that converts a decimal number to Roman number. Decimal Number is accepted as command line input at the time of execution.
Program :
Java program that converts a decimal number to Roman number. Decimal Number is accepted using Scanner class at the time of execution.
import java.util.Scanner; public class DecimalToRoman { private static String toRoman(int num) { String[] romanCharacters = { "M", "CM", "D", "C", "XC", "L", "X", "IX", "V", "I" }; int[] romanValues = { 1000, 900, 500, 100, 90, 50, 10, 9, 5, 1 }; String result = ""; for (int i = 0; i < romanValues.length; i++) { int numberInPlace = num / romanValues[i]; if (numberInPlace == 0) continue; result += numberInPlace == 4 && i > 0? romanCharacters[i] + romanCharacters[i - 1]: new String(new char[numberInPlace]).replace("\0",romanCharacters[i]); num = num % romanValues[i]; } return result; } public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.print("Enter a number : "); int decimal = scanner.nextInt(); System.out.println(toRoman(decimal)); } }
Output :
Enter a number : 1234
MCCXXXIV
Java program that converts a decimal number to Roman number. Decimal Number is accepted as command line input at the time of execution.
public class DecimalToRoman { private static String toRoman(int num) { String[] romanCharacters = { "M", "CM", "D", "C", "XC", "L", "X", "IX", "V", "I" }; int[] romanValues = { 1000, 900, 500, 100, 90, 50, 10, 9, 5, 1 }; String result = ""; for (int i = 0; i < romanValues.length; i++) { int numberInPlace = num / romanValues[i]; if (numberInPlace == 0) continue; result += numberInPlace == 4 && i > 0? romanCharacters[i] + romanCharacters[i - 1]: new String(new char[numberInPlace]).replace("\0",romanCharacters[i]); num = num % romanValues[i]; } return result; } public static void main(String[] args) { if(args.length<1 || args.length>1){ System.out.println("Wrong input"); }else{ String number = args[0]; int decimal = Integer.parseInt(number); System.out.println(toRoman(decimal)); } } }
Objectives :
- Decimal to Binary Conversion
- Converting Decimal to Binary
- Converting Decimal Number to Binary format
- Write a program to convert decimal to binary
- Write a program to convert decimal number to binary format
- Write a program to convert positive decimal number to binary format
- Write a program to convert decimal to binary using Scanner class
- Write a program to convert decimal to binary, take input using Scanner class
Java Program to convert Decimal to Binary :
public class DecimalToBinary { public void toBinary(int number){ int binary[] = new int[25]; int n = 0; // Convert Decimal to Binary while(number > 0){ binary[n++] = number%2; number = number/2; } // Print Binary number for(int i = n-1;i >= 0;i--){ System.out.print(binary[i]); } } public static void main(String[] args){ DecimalToBinary obj = new DecimalToBinary(); obj.toBinary(14); } }
Output :
1110
Java Program to convert Decimal to Binary using Scanner class :
import java.util.Scanner; public class DecimalToBinary { public void toBinary(int number){ int binary[] = new int[14]; int n = 0; // Convert Decimal to Binary while(number > 0){ binary[n++] = number%2; number = number/2; } // Print Binary Number for(int i = n-1;i >= 0;i--){ System.out.print(binary[i]); } } public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.print("Enter a number: "); int num= scanner.nextInt(); DecimalToBinary obj = new DecimalToBinary(); obj.toBinary(num); } }
Output :
Enter a number: 14
1110
Objectives :
- Write a Java program to find prime number upto N number
- Write a Java program to print prime number upto N number
- Write a Java program to find prime number upto N number using Command Line Arguments
- Write a Java Program to find prime number upto N number via Command Line Arguments
- Write a Java program to find prime number upto N number using Scanner class
Java Program / Code :
Method 1 : Java Program to find Prime Number upto N number using Scanner class
import java.util.Scanner; class PrimeNumber { public static void main(String[] args) { int n,p; Scanner s=new Scanner(System.in); System.out.println(“Enter number : ”); n=s.nextInt(); for(int i=2;i<n;i++) { p=0; for(int j=2;j<i;j++) { if(i%j==0) p=1; } if(p==0){ System.out.println(i); } } } }
Method 2 : Java Program to find Prime Number upto N number using Scanner class and writing function to find prime number
Method isPrime() for checking if a number is prime or not
public class PrimeNumber{ public boolean isPrime(int num) { if ( num < 2 ){ return false; } for (int i = 2; i <= Math.sqrt(num); i++) { if ( num % i == 0 ) { return false; } } return true; } } // Mock Test Class to test above code import java.util.Scanner; public class Demo { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.println("Please enter a number: "); int num = scanner.nextInt(); if ( num < 2 ) { System.out.println("\n There are no Prime Numbers available"); System.exit(0); } System.out.println("\n Prime Numbers from 1 to "+ num); PrimeNumber primeNum = new PrimeNumber(); for (int i = 3; i <= num; i++) { if ( primeNum.isPrime(i) ) { System.out.print(", " + i); } } } }
Method 3 : Java Program to find Prime Number upto N number using Command line input
class PrimeNumber { public static void main(String[] args) { int n,p; n=Integer.parseint(args[0]); for(int i=2;i<n;i++) { p=0; for(int j=2;j<i;j++) { if(i%j==0) p=1; } if(p==0){ System.out.println(i); } } } }
Steps to run above program via command line :
- Compilation : C:\JavaPrograms>javac PrimeNumber.java
- Interpretation : C:\JavaPrograms>java PrimeNumber 20
Output :
2
3
5
7
11
13
17
19