function readOnly(count){ }
Starting November 20, the site will be set to read-only. On December 4, 2023,
forum discussions will move to the Trailblazer Community.
+ Start a Discussion
Manogna KoviManogna Kovi 

Write an apex program to print prime numbers

v varaprasadv varaprasad
Hi Manogna,

Check once below links :

https://success.salesforce.com/answers?id=9063A000000iRYGQA2
https://developer.salesforce.com/forums/?id=906F00000005J7fIAE


Hope this helps you!
If my answer helps resolve your query, please mark it as the 'Best Answer' & upvote it to benefit others.

Thanks
Varaprasad
@For Support: varaprasad4sfdc@gmail.com
Blog: http://salesforceprasad.blogspot.com/


Salesforce latest interview questions  :
https://www.youtube.com/channel/UCOcam_Hb4KjeBdYJlJWV_ZA?sub_confirmation=1




 
v varaprasadv varaprasad
public class PrimeNumbers {
    public void prime(){
    for(integer i=1;i<=100;i++)
    {
        integer count=0;
        for(integer j=i; j>=1;j--)
        {
            
            if(math.mod(i,j)==0 )
            {
                count++;
            }
        }
        if(count==2 || count==1){
            
                         system.debug(i);
                   
                }                     
                 
            else{
               //system.debug('not prime');      
                }
    }
  }

}

 
Malika Pathak 9Malika Pathak 9

Hi Manogna,

public class FindPrimeNumber{
    public void getPrime(){
integer x=0;
    for(x=0;x<10;x++)
    {
        integer count=0;
integer y=0;
        for( y=x; y>=1;y--)
        {
            
            if(math.mod(x,y)==0 )
            {
                count++;
            }
        }
        if(count==2 || count==1){
            
                         system.debug(x);
                   
                }                     
                 
            else{
                system.debug('This is not prime number ');      
                }
    }
  }

}

if you find this helpful mark it as the best answer.
Neeraj Agrawal 17Neeraj Agrawal 17
Hi, Please check below to check whether number is prime 
public class PrimeNumber {
    
  static integer remainder;
  static boolean isPrime=true;
    
    public static void func(Integer num){
        
        for(integer i=2;i<=num/2;i++)
  {
            remainder=math.mod(num,i);
            System.debug(num+ 'Divided by'+ i + 'gives a remainder'+remainder);
            
       //if remainder is 0 than numberToCheckber is not prime and break loop. Elese continue loop
     if(remainder==0)
     {
        isPrime=false;
        break;
     }
  }

if(isPrime)
{
     System.debug(num + 'is a Prime numberToCheckber');
}
  else
  {
     System.debug(num + 'is not a Prime numberToCheckber');
  }
    }        
    }
Ankit Gupta SFDCLearnerAnkit Gupta SFDCLearner
Hi Use below apex code and VF page for test.
Apex class

public class calculation {
  Public integer myInputQueryString {
    get;
    set;
  }
  Public string myoutputString {
    get;
    set;
  }
string val = '';
  Public void myInputQuery() {
    if (myInputQueryString != null) {
      system.debug('not null');
      
      for (integer i = 0; i < myInputQueryString; i++) {

        if (math.mod(i, 2) == 0) {
          system.debug('this is even number: ' + i);

          val = val + string.valueOf(i) + ', ';
          myoutputString = val;

        }

      }
      myInputQueryString = 0;
    } 
  }

  Public void myOddNumbers() {
    if (myInputQueryString != null) {
      system.debug('not null');
       
      for (integer i = 0; i < myInputQueryString; i++) {

        if (math.mod(i, 2) != 0) {
          system.debug('this is even number: ' + i);

          val = val + string.valueOf(i) + ', ';
          myoutputString = val;

        }

      }
      myInputQueryString = 0;
    } 
  }
  Public void myPrimeNumbers() {

    if (myInputQueryString != null) {
      system.debug('not null');
       
      for (integer i = 0; i < myInputQueryString; i++) {
        integer count = 0;
        for (integer j = i; j >= 1; j--) {

          if (math.mod(i, j) == 0) {
            count++;
          }
        }
        if (count == 2 || count == 1) {

          system.debug(i);
           val = val + string.valueOf(i) + ', ';
          myoutputString = val;

        }
      }
    }

  }
}

VF Page
<apex:page controller="calculation" id="vfPageId">
  <apex:form id="formId">
    <script>
      function CheckNull() {
        //alert('ff');
        debugger;
        var dd = document.getElementById("vfPageId:formId:inputnum1").value;
        if (dd == '') {
          alert('Please enter number');
        }
      }
    </script> Input Number:
    <apex:inputText value="{!myInputQueryString}" id="inputnum1" />
    <apex:pageblock id="evenPBId">
      <apex:commandButton value="Even Numbers" reRender="DisplayEvenID" action="{!myInputQuery}" onClick="CheckNull();" />
      <b>Even Numbers are: </b>
      <apex:outputText value="{!myoutputString}" id="DisplayEvenID" />
      <br />
      <apex:commandButton value="Odd Numbers" reRender="DisplayOddID" action="{!myOddNumbers}" onClick="CheckNull();" />
      <b>Odd Numbers are: </b>
      <apex:outputText value="{!myoutputString}" id="DisplayOddID" />
      <br />
      <apex:commandButton value="Prime Numbers" reRender="DisplayPrimeID" action="{!myPrimeNumbers}" onClick="CheckNull();" />
      <b>Prime Numbers are: </b>
      <apex:outputText value="{!myoutputString}" id="DisplayPrimeID" />
    </apex:pageblock>
  </apex:form>
</apex:page>
Shruthi MN 88Shruthi MN 88
@Neeraj Agrawal 17

why have you used n/2 when we can do without that