Java Plan To Impress Prime Numbers From Ane To 100

In this article, I'll part yous a unproblematic work near writing a Java programme to impress prime numbers upwards to a given publish e.g. tell prime numbers from 1 to 100. It's 1 of the most mutual coding exercises for programmers learning inwards Java, equally it gives yous an chance to acquire to a greater extent than near essential operator inwards Java Programming. The fundamental hither is that yous cannot purpose a library portion which tin shipping away exactly your job, yous involve to devise the algorithm for checking prime publish past times yourself. One of the most pop algorithms for generating prime is Sieve of Eratosthenes,  which nosotros get got discussed earlier, but inwards this post, nosotros volition get got a simpler approach. We'll commencement write a portion to cheque whether a publish is prime or non in addition to thus nosotros loop through commencement 100 numbers i.e. from 1 to 100 in addition to impress entirely those which passed the prime test. Btw, if yous are looking for around serious programming coding inquiry for the interview, thus yous tin shipping away too get got a await at Cracking the coding interview, which contains to a greater extent than than 150 coding inquiry amongst solutions.

How to cheque if a publish is prime or not

H5N1 publish is said to hold upwards prime if it's non divisible past times whatsoever publish other than itself e.g. 2, three or 5. 1 is non counted equally a prime number, thus the lowest prime publish is 2. One of the easiest agency to cheque whether a publish is prime or not is to loop from 2 to the publish itself in addition to checks if it's divisible past times whatsoever publish inwards betwixt or not.

You tin shipping away produce that cheque past times using modulus operator inwards Java, which provide naught if a publish is perfectly divisible past times around other number. If the publish yous are checking is non divisible past times anyone thus it's a prime publish otherwise, it's non a prime number.

But this logic tin shipping away hold upwards farther optimized to entirely loop through the foursquare rootage of the publish instead of the publish itself, equally shown inwards below example. This volition brand the Java programme fast for checking large prime numbers.



Here is a listing of all prime numbers betwixt 1 in addition to 100:

An optimized agency to generate Prime numbers from 1 to 100

/**  * Java Program to impress prime numbers from 1 to 100  *  * @author Javin Paul  */ public class PrimeNumberGenerator {      public static void main(String args[]) {          // impress prime numbers from 1 - 100         System.out.println("Prime numbers from 1 to 100 ");          for (int i = 2; i <= 100; i++) {             if (isPrime(i)) {                 System.out.println(i);             }         }     }      /*      * An optimized to cheque if a publish is prime or not.      */     public static boolean isPrime(int num) {         if (num == 2 || num == 3) {             return true;         }          if (num % 2 == 0 || num % 3 == 0) {             return false;         }          for (int i = 3; i < Math.sqrt(num); i += 2) {             if (num % i == 0 || num % Math.sqrt(num) == 0) {                 return false;             }         }         return true;      } }  Output: Prime numbers from 1 to 100  2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
 

That's all near how to impress prime numbers inwards Java from 1 to 100.  Let me know if yous uncovering whatsoever põrnikas on this programme or yous intend if this programme volition non operate inwards whatsoever specific scenario. This looks much to a greater extent than optimized than looping till the publish itself.

Here are dyad of to a greater extent than coding problems for practice:

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• Write a programme to cheque if a publish is a ability of 2 or not? (solution)
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• How to uncovering duplicate characters from String inwards Java? (solution)
• How to contrary an int variable inwards Java? (solution)
• How to cheque if a twelvemonth is a leap twelvemonth inwards Java? (answer)
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• How to impress Pyramid pattern inwards Java? (solution)
• How to cheque if a given publish is prime or not? (solution)
• How to solve FizzBuzz work inwards Java? (solution)
• Write a programme to impress the highest frequency give-and-take from a text file? (solution)
• How to withdraw duplicate elements from ArrayList inwards Java? (solution)
• How to uncovering if given String is a palindrome inwards Java? (solution)

Further Reading

The Coding Interview Bootcamp: Algorithms + Data Structures
Data Structures in addition to Algorithms: Deep Dive Using Java
Algorithms in addition to Data Structures - Part 1 in addition to 2