Primzahl in Java: Primzahl ist eine Zahl, die größer als 1 ist und durch 1 oder nur durch sich selbst geteilt wird. Mit anderen Worten: Primzahlen können nicht durch andere Zahlen als sich selbst oder 1 geteilt werden. Beispielsweise sind 2, 3, 5, 7, 11, 13, 17 ... die Primzahlen.
Hinweis: 0 und 1 sind keine Primzahlen. Die 2 ist die einzige gerade Primzahl, da alle anderen geraden Zahlen durch 2 teilbar sind.
Sehen wir uns das Primzahlprogramm in Java an. In diesem Java-Programm nehmen wir eine Zahlenvariable und prüfen, ob die Zahl eine Primzahl ist oder nicht.
public class PrimeExample{ public static void main(String args[]){ int i,m=0,flag=0; int n=3;//it is the number to be checked m=n/2; if(n==0||n==1){ System.out.println(n+' is not prime number'); }else{ for(i=2;i<=m;i++){ if(n%i="=0){" system.out.println(n+' is not prime number'); flag="1;" break; } if(flag="=0)" { end of else < pre> <span> Test it Now </span> <p>Output:</p> <pre> 3 is prime number </pre> <h2>Prime Number Program using Method in Java</h2> <pre> public class PrimeExample2{ static void checkPrime(int n){ int i,m=0,flag=0; m=n/2; if(n==0||n==1){ System.out.println(n+' is not prime number'); }else{ for(i=2;i<=m;i++){ if(n%i="=0){" system.out.println(n+' is not prime number'); flag="1;" break; } if(flag="=0)" { end of else public static void main(string args[]){ checkprime(1); checkprime(3); checkprime(17); checkprime(20); < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 is not prime number 3 is prime number 17 is prime number 20 is not prime number </pre> <h2>Prime Number Program in Java (Another way)</h2> <p>You can also use a method where number is not predefined. Here, user has to put the number to check if the number is prime.</p> <pre> import java.util.Scanner; import java.util.Scanner; public class PrimeExample3 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter a number : '); int n = s.nextInt(); if (isPrime(n)) { System.out.println(n + ' is a prime number'); } else { System.out.println(n + ' is not a prime number'); } } public static boolean isPrime(int n) { if (n <= 1) { return false; } for (int i="2;" < math.sqrt(n); i++) if (n % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample1</strong> <h2>Find prime numbers between two numbers</h2> <p>You can also find prime numbers between two specified numbers.</p> <pre> import java.util.Scanner; public class PrimeExample4 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter the first number : '); int start = s.nextInt(); System.out.print('Enter the second number : '); int end = s.nextInt(); System.out.println('List of prime numbers between ' + start + ' and ' + end); for (int i = start; i <= end; i++) { if (isprime(i)) system.out.println(i); } public static boolean isprime(int n) (n <="1)" return false; for (int i="2;" % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample2</strong> </=></pre></=></pre></=m;i++){></pre></=m;i++){> Primzahlprogramm mit Methode in Java
public class PrimeExample2{ static void checkPrime(int n){ int i,m=0,flag=0; m=n/2; if(n==0||n==1){ System.out.println(n+' is not prime number'); }else{ for(i=2;i<=m;i++){ if(n%i="=0){" system.out.println(n+\' is not prime number\'); flag="1;" break; } if(flag="=0)" { end of else public static void main(string args[]){ checkprime(1); checkprime(3); checkprime(17); checkprime(20); < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 is not prime number 3 is prime number 17 is prime number 20 is not prime number </pre> <h2>Prime Number Program in Java (Another way)</h2> <p>You can also use a method where number is not predefined. Here, user has to put the number to check if the number is prime.</p> <pre> import java.util.Scanner; import java.util.Scanner; public class PrimeExample3 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter a number : '); int n = s.nextInt(); if (isPrime(n)) { System.out.println(n + ' is a prime number'); } else { System.out.println(n + ' is not a prime number'); } } public static boolean isPrime(int n) { if (n <= 1) { return false; } for (int i="2;" < math.sqrt(n); i++) if (n % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample1</strong> <h2>Find prime numbers between two numbers</h2> <p>You can also find prime numbers between two specified numbers.</p> <pre> import java.util.Scanner; public class PrimeExample4 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter the first number : '); int start = s.nextInt(); System.out.print('Enter the second number : '); int end = s.nextInt(); System.out.println('List of prime numbers between ' + start + ' and ' + end); for (int i = start; i <= end; i++) { if (isprime(i)) system.out.println(i); } public static boolean isprime(int n) (n <="1)" return false; for (int i="2;" % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample2</strong> </=></pre></=></pre></=m;i++){> Primzahlprogramm in Java (anders)
Sie können auch eine Methode verwenden, bei der die Zahl nicht vordefiniert ist. Hier muss der Benutzer die Zahl eingeben, um zu überprüfen, ob die Zahl eine Primzahl ist.
import java.util.Scanner; import java.util.Scanner; public class PrimeExample3 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter a number : '); int n = s.nextInt(); if (isPrime(n)) { System.out.println(n + ' is a prime number'); } else { System.out.println(n + ' is not a prime number'); } } public static boolean isPrime(int n) { if (n <= 1) { return false; } for (int i="2;" < math.sqrt(n); i++) if (n % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample1</strong> <h2>Find prime numbers between two numbers</h2> <p>You can also find prime numbers between two specified numbers.</p> <pre> import java.util.Scanner; public class PrimeExample4 { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print('Enter the first number : '); int start = s.nextInt(); System.out.print('Enter the second number : '); int end = s.nextInt(); System.out.println('List of prime numbers between ' + start + ' and ' + end); for (int i = start; i <= end; i++) { if (isprime(i)) system.out.println(i); } public static boolean isprime(int n) (n <="1)" return false; for (int i="2;" % 0) true; pre> <p>Output:</p> <strong>Use image PrimeExample2</strong> </=></pre></=>