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Beginner coding challenges
Practise beginner with 95 coding challenges, from easy to hard. Every challenge runs in your browser with instant tests, an AI review of your code and community solutions to compare.
Easy · 89 Medium · 6
Skills you'll practise: CountingArithmeticDigit extractionFormulasListsString splitting2D listsConditionsDivisibilityLoopsModuloSingle pass
- Python · C++ · C#
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All challenges
Search by topic, language, or difficulty.
Easy
Sum an Array
Add up all values in a list.
You'll learn
AccumulatorsEmpty-list cases
No solutions yet
Easy
Difference of Squares
Subtract the sum of squares from the square of the sum.
You'll learn
FormulasArithmetic
No solutions yet
Easy
Chess Square Color
Determine the color of a square on an 8 by 8 board.
You'll learn
CoordinatesParity
No solutions yet
Easy
Hours, Minutes, and Seconds
Convert a duration in seconds to a compact readable string.
You'll learn
Time unitsString formatting
No solutions yet
Easy
Smallest Digit
Find the smallest decimal digit of a positive integer.
You'll learn
Digit extractionTracking a minimum
No solutions yet
Easy
Largest Digit
Find the largest decimal digit of a positive integer.
You'll learn
Digit extractionTracking a maximum
No solutions yet
Easy
Factorial
Multiply all positive integers up to n.
You'll learn
LoopsRunning product
No solutions yet
Easy
Sum of Digits
Add up the decimal digits of a positive integer.
You'll learn
Modulo and divisionWhile loops
No solutions yet
Easy
Triangular Number
Add the integers from 1 through n.
You'll learn
LoopsArithmetic series
No solutions yet
Easy
Square a Number
Multiply an integer by itself.
You'll learn
FunctionsArithmetic
No solutions yet
Easy
Reverse a Number
Reverse the decimal digits of a positive integer.
You'll learn
Digit extractionBuilding numbers
No solutions yet
Easy
Count Digits
Count the decimal digits of a positive integer.
You'll learn
Integer divisionCounting loops
No solutions yet
Easy
One Shared Configuration
Simulate a singleton settings object: every part of the program reads and writes the same instance.
You'll learn
SingletonShared state
No solutions yet
Easy
Bank Account Rules
Protect an account's balance behind deposit and withdraw rules, rejecting invalid operations.
You'll learn
EncapsulationBusiness rules
No solutions yet
Easy
First Invalid Age
Validate typed ages and report where the first bad entry is instead of letting the program crash.
You'll learn
ValidationParsing
No solutions yet
Easy
Vehicle Tolls
Charge tolls for motorbikes, cars and trucks where trucks extend the basic vehicle rule with axles.
You'll learn
InheritanceMethod overriding
No solutions yet
Easy
Count Log Levels
Read the lines of a log file and count how many are INFO, WARNING and ERROR.
You'll learn
Reading linesString splitting
No solutions yet
Easy
Sum the Valid Numbers
Add up the entries that are whole numbers and skip everything else, the way try/except handles bad input.
You'll learn
Try/exceptInput validation
No solutions yet
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