7 Beginner Code Problems? Here's What Works in 2025
Ready to start coding? Tackle these 7 essential beginner code problems with explanations and solutions to build your confidence and sharpen your problem-solving skills.
Daniel Carter
Senior Software Engineer and mentor passionate about helping new developers succeed.
Why You Need to Solve Problems to Learn Code
Staring at a blank code editor can feel intimidating. You've watched the tutorials, you understand the syntax for loops and variables, but making the leap from theory to practical application is a huge hurdle. This is where the real learning begins. Reading a cookbook doesn't make you a chef; you have to get in the kitchen and start cooking. Similarly, to become a developer, you must write code, solve problems, and, yes, even make a few mistakes.
Solving small, targeted coding problems is like a workout for your brain. It builds mental muscle, strengthens your grasp of core concepts, and develops the most critical skill for any developer: problem-solving. Each challenge you overcome builds confidence and prepares you for more complex tasks. The seven problems below are classic rites of passage for new programmers. They are designed to test your understanding of fundamental concepts in a manageable way. Let's dive in!
The 7 Essential Beginner Code Problems
We've curated this list to cover the most important foundational skills, from manipulating data to controlling program flow. For each problem, we'll explain the task, why it's a valuable exercise, and provide a simple solution in JavaScript, a popular language for beginners.
1. Reverse a String
The Task: Write a function that takes a string as input and returns a new string with the characters in reverse order. For example, `"hello"` should become `"olleh"`.
Why it's useful: This is the quintessential beginner's problem. It teaches you to think about strings as a sequence of characters, often by converting them to an array. It’s a great introduction to basic data manipulation, array methods, and looping constructs.
Example Solution (JavaScript):
function reverseString(str) {
// Easiest method: split into an array, reverse it, and join back together.
return str.split('').reverse().join('');
}
console.log(reverseString("world")); // Outputs: "dlrow"2. FizzBuzz
The Task: Write a program that prints numbers from 1 to 100. But for multiples of three, print `"Fizz"` instead of the number. For multiples of five, print `"Buzz"`. For numbers which are multiples of both three and five, print `"FizzBuzz"`.
Why it's useful: FizzBuzz is a famous screening question for programming jobs because it instantly reveals if a candidate understands basic program flow. It forces you to use loops (like `for`) and conditional logic (`if`, `else if`, `else`). The key is handling the `"FizzBuzz"` case first, which is a common stumbling block.
Example Solution (JavaScript):
for (let i = 1; i <= 100; i++) {
if (i % 15 === 0) { // or (i % 3 === 0 && i % 5 === 0)
console.log("FizzBuzz");
} else if (i % 3 === 0) {
console.log("Fizz");
} else if (i % 5 === 0) {
console.log("Buzz");
} else {
console.log(i);
}
}3. Check for Palindrome
The Task: Write a function that checks if a given string is a palindrome. A palindrome is a word or phrase that reads the same forwards and backward, ignoring punctuation, case, and spacing. Examples include `"racecar"`, `"level"`, and `"A man, a plan, a canal: Panama"`.
Why it's useful: This problem builds directly on the string reversal concept. It adds a layer of complexity by requiring you to "clean" the input string first—removing non-alphanumeric characters and converting it to a consistent case. It's a great exercise in string methods and comparison logic.
Example Solution (JavaScript):
function isPalindrome(str) {
// 1. Clean the string: lowercase and remove non-alphanumeric chars
const cleanedStr = str.toLowerCase().replace(/[^a-z0-9]/g, '');
// 2. Reverse the cleaned string
const reversedStr = cleanedStr.split('').reverse().join('');
// 3. Compare the cleaned string to its reversed version
return cleanedStr === reversedStr;
}
console.log(isPalindrome("RaceCar")); // Outputs: true
console.log(isPalindrome("hello")); // Outputs: false4. Find the Largest Number in an Array
The Task: Write a function that takes an array of numbers and returns the largest number in that array.
Why it's useful: This problem introduces the concept of iterating through a collection of data (an array) while keeping track of a value. You'll set an initial maximum and then compare every other element to it, updating the maximum whenever you find a larger number. This pattern of iterating and tracking is fundamental in programming.
Example Solution (JavaScript):
function findLargestNumber(arr) {
if (arr.length === 0) return undefined; // Handle empty array case
let largest = arr[0]; // Assume the first element is the largest
for (let i = 1; i < arr.length; i++) {
if (arr[i] > largest) {
largest = arr[i]; // Found a new largest number, so update it
}
}
return largest;
}
console.log(findLargestNumber([1, 5, 2, 9, 3])); // Outputs: 95. Calculate a Factorial
The Task: Write a function that calculates the factorial of a non-negative integer. The factorial of a number `n` (denoted as `n!`) is the product of all positive integers up to `n`. For example, `5! = 5 * 4 * 3 * 2 * 1 = 120`. By definition, `0! = 1`.
Why it's useful: Calculating a factorial is a perfect introduction to two important programming concepts: iteration and recursion. While it can be solved with a simple `for` loop (iteration), it's also a classic example used to teach recursion, where a function calls itself to solve a smaller version of the same problem.
Example Solution (Iterative):
function factorial(num) {
if (num < 0) return undefined; // Factorial is not defined for negative numbers
if (num === 0) return 1;
let result = 1;
for (let i = 2; i <= num; i++) {
result *= i;
}
return result;
}
console.log(factorial(5)); // Outputs: 1206. The Fibonacci Sequence
The Task: Write a function that takes a number `n` and returns an array containing the first `n` elements of the Fibonacci sequence. The sequence starts with 0 and 1, and each subsequent number is the sum of the two preceding ones: `0, 1, 1, 2, 3, 5, 8, 13, ...`.
Why it's useful: Like the factorial problem, Fibonacci is a cornerstone for understanding recursion. However, the iterative solution is often more efficient and is a great exercise in building up an array based on previous values. It teaches you to manage state (the last two numbers) within a loop.
Example Solution (Iterative):
function fibonacciSequence(n) {
if (n <= 0) return [];
if (n === 1) return [0];
const sequence = [0, 1];
for (let i = 2; i < n; i++) {
const nextNumber = sequence[i - 1] + sequence[i - 2];
sequence.push(nextNumber);
}
return sequence;
}
console.log(fibonacciSequence(8)); // Outputs: [0, 1, 1, 2, 3, 5, 8, 13]7. Anagram Checker
The Task: Write a function that takes two strings and determines if they are anagrams of each other. Anagrams are words formed by rearranging the letters of another, such as `"listen"` and `"silent"`.
Why it's useful: This is a step up in difficulty. It requires more thoughtful data manipulation. The most intuitive solution for beginners involves cleaning the strings, splitting them into arrays of characters, sorting those arrays, and then comparing the resulting strings. This reinforces sorting algorithms and logical comparison on a deeper level.
Example Solution (JavaScript):
function areAnagrams(str1, str2) {
// Helper function to clean and sort the string
const processString = (str) => str.toLowerCase().replace(/[^a-z0-9]/g, '').split('').sort().join('');
return processString(str1) === processString(str2);
}
console.log(areAnagrams("Listen", "Silent")); // Outputs: true
console.log(areAnagrams("Dormitory", "dirty room##")); // Outputs: trueComparing the Coding Problems
Each problem targets different but overlapping skills. Here's a quick comparison to help you understand what you're practicing with each one.
| Problem | Key Concepts Taught | Difficulty |
|---|---|---|
| Reverse a String | String/Array methods, Looping | Easy |
| FizzBuzz | Loops, Conditionals (if/else), Modulo operator | Easy |
| Palindrome Check | String manipulation, Comparison, Conditionals | Easy |
| Find Largest Number | Array iteration, Tracking state (variables) | Easy |
| Calculate a Factorial | Loops, Accumulator pattern, Introduction to recursion | Medium |
| Fibonacci Sequence | Array building, State management, Recursion | Medium |
| Anagram Checker | Advanced string manipulation, Sorting, Data normalization | Medium |
What's Next? From Problems to Projects
Congratulations! Working through these problems is a significant step. You've moved from passive learning to active problem-solving. But don't stop here. The key to growth is consistency. Re-solve these problems in a different way. If you used a loop, try a different kind of loop or a built-in method. If you solved it iteratively, research the recursive solution.
Once you feel comfortable, seek out more challenges on platforms like LeetCode, HackerRank, or Codewars. As you gain confidence, start thinking about small projects. Could you build a simple calculator? A to-do list application? A weather app? Projects are where you'll learn to connect all these small pieces into a functioning whole. Keep practicing, stay curious, and you'll be building amazing things before you know it.