Return Min-Max Numbers in Apex

Want to figure out the smallest and largest numbers in a list using Apex? You’ve come to the right place!

In this blog post, we’ll walk through a method that takes a list of integers and returns the maximum and minimum numbers from it. This is a super common task whether you’re working with scores, prices, or even temperature data. 📊

This simple logic is beginner-friendly and helps you get more comfortable with loops, comparisons, and list handling in Apex.

🧠 What Are We Trying to Do?

Let’s say we pass this list to our method:

[7, 5, 65, 799, 8]

We want to:

• Find the largest number (799)

• Find the smallest number (5)

• Return both in a new list: [799, 5]

That’s exactly what this method does!

🔍 Code Explanation

public with sharing class ApexUseCaseSeventeen {
    
    public static List<Integer> findMinAndMax(List<Integer> listOfNumbers){

We define a class called ApexUseCaseSeventeen, and inside it, a static method called findMinAndMax that accepts a list of integers.

        List<Integer> minAndMaxList = new List<Integer>();
        if(listOfNumbers.size() > 0){

We create an empty list to hold the min and max values. Then we check if the input list is not empty to avoid errors.

            Integer minNumber = listOfNumbers[0];
            Integer maxNumber = listOfNumbers[0];

We initialize both minNumber and maxNumber to the first number in the list. We’ll compare all other numbers to these.

            for(Integer eachNum : listOfNumbers){
                if(eachNum >= maxNumber){
                    maxNumber = eachNum;
                }
                if(eachNum < minNumber){
                    minNumber = eachNum;
                }
            }

We loop through each number:

• If the number is greater than or equal to the current max, update maxNumber

• If it’s smaller than the current min, update minNumber

Simple logic. 💡

            minAndMaxList.add(maxNumber);
            minAndMaxList.add(minNumber);
        }

        return minAndMaxList;
    }
}

After the loop finishes, we add both maxNumber and minNumber to our result list and return it.

✅ Why This Is Useful

This kind of logic is incredibly helpful when you need to:

• Summarize data (like highest/lowest scores)

• Compare prices or metrics

• Build dashboards or reports

It’s also a great exercise in working with:

• Loops

• If-conditions

• Lists and return values

You can easily expand it to:

• Work with decimals

• Return a map with keys like "min" and "max"

• Include null checks or validations

🧾 Final Code Snippet

public with sharing class ApexUseCaseSeventeen {
    public static List<Integer> findMinAndMax(List<Integer> listOfNumbers){
        List<Integer> minAndMaxList = new List<Integer>();
        if(listOfNumbers.size() > 0){
            Integer minNumber = listOfNumbers[0];
            Integer maxNumber = listOfNumbers[0];

            for(Integer eachNum : listOfNumbers){
                if(eachNum >= maxNumber){
                    maxNumber = eachNum;
                }
                if(eachNum < minNumber){
                    minNumber = eachNum;
                }
            }

            minAndMaxList.add(maxNumber);
            minAndMaxList.add(minNumber);
        }

        return minAndMaxList;
    }
}

🎥 Watch It in Action!

Want to see how it works step-by-step? Check out my quick demo where I run this method using sample data in the Developer Console.