I have 3 text fields

  • startnumber
  • Endnumber
  • Limit number

startnumber indicates --->The starting point of random number

End number --> ending point of random number.

Limit number-->how many number we have to display

For example: startnumber is 10 and endnumber is 100 ,if limit number is 5 then I have to display 5 random numbers (without duplicates)

Problem facing:

  • How to display random numbers based on limits without duplicates

For example if Limit number is 5 in between 10to 100 For example I got below result:{22,44,67,11,11}.
Here 11 is duplicate,using set I can avoid that value but result will become 4.(itsnot accepted).
Instead of 11,I need to display other number then result will becomes 5.(its accepted), its like [Limit number=displayed numbers]

<apex:page controller="randomUtilities">
<apex:form >
    <apex:pageBlock >
        start number: <apex:inputText value="{!startNumber}"/> 
        End Number: <apex:inputText value="{!endNumber}"/> 
        Limit number:<apex:inputText value="{!limitNumber}"/> 
        <apex:pageBlockButtons location="bottom">
            <apex:commandButton action="{!showresult}" value="Here you go...." reRender="as2"/>

    <apex:outputPanel id="as2">
    <apex:pageblock >   
        <apex:pageBlockTable value="{!aclist1}" var="a">
                         <apex:column value="{!a}"/>



public class randomUtilities {
public integer startNumber{get;set;}
public integer endNumber{get;set;}
public integer limitNumber{get;set;}
public list<integer> aclist{get;set;}
private static integer getRandomNumberInRange(integer min, integer max) {
    return (integer)(Math.random() * ((max - min) + 1)) + min;
 public PageReference  showresult(){
    aclist=new List<integer>();
    for (integer i = 0; i <limitNumber; i++) {

        integer a=getRandomNumberInRange(startNumber, endNumber);
    return null; }}   
  • I would anyway use a set and than do a while loop that checks the size of your set. if its < than limit number than add another random number
    – utm
    Jun 29 '18 at 11:15
  • @Annappa instead of using list you can use set, so that you can get unique numbers. Use Set and try the same Jun 29 '18 at 11:45
  • I mentioned that Point Atul.this one is very importnat for me: Limit number=displayed numbers] Jun 29 '18 at 11:52

Try in this way.

Integer i = 1;
Integer j= 100; 
set<Integer> setInteger = new set<Integer>();

while (setInteger.size() < 5) 
    Integer intRandom = (integer)(Math.random()*(j-i+1)+i);

enter image description here

  • 1
    The if(...contains...) clause is not necessary. A set will not add the same value twice. That's the point of a set.
    – sfdcfox
    Jun 30 '18 at 2:58

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