- 01Getting Started
- 02Your First Output (Console.WriteLine)
- 03Working with Variables
- 04Conditionals (if statements)
- 05Loops (for statements)
- 06Writing a Method (Function)
- 07Working with Arrays
- 08Loops (while statements)
- 09Classes (Object-Oriented Programming)
- 10Error Handling (try-catch)
- 11Sorting an Array
- 12Recursive Functions
- 13Using the Standard Library
- 14The switch Statement
- 15The Ternary Operator
- 16Inheritance (Extending a Class)
- 17Writing Comments
- 18Logical Operators (&&, ||, !)
- 19Constants (const)
- 20Splitting and Joining Strings (Split, Join)
- 21Writing Null-Safe Code (the ?? operator)
- 22Searching an Array (Looking Through It in a Loop)
- 23Transforming an Array (LINQ Select)
- 24Two-Dimensional Arrays (Tabular Data)
- 25Writing a Custom Exception Class
- 26Default Parameter Values
- 27Working with HashSet (Sets)
- 28Checking Correctness (Your First Step into Testing)
- 29Higher-Order Functions (Passing a Function as an Argument)
- 30Stacks and Queues (Basic Data Structures)
- 31Type Conversion (Casting) Basics
- 32Intro to Regular Expressions (Pattern Matching)
- 33The Binary Search Algorithm
- 34Building a Caesar Cipher (a Character-Shifting Cipher)
- 35Understanding How Bubble Sort Works
- 36Building and Displaying Dates (Basic Year/Month/Day Operations)
- 37Writing Multiple Test Cases Together
- 38Speeding Up Calculations with Memoization (Caching)
- 39Normalizing Strings (Trim, Unifying Case)
- 40Shallow Copy vs. Deep Copy
- 41Enum (Enumerated Types) Basics
- 42Flattening an Array
- 43Reversing a String and Checking for Palindromes
- 44Pairing Up Two Arrays (the zip operation)
- 45Rounding Numbers (Floor, Ceiling, Round)
- 46Multi-Line Strings (Verbatim Strings)
- 47Functions That Return Multiple Values (Tuples)
- 48Finding the GCD and LCM (the Euclidean Algorithm)
- 49Formatting Numbers (Padding Digits, Decimal Places)
- 50Cleanup Logic with try/catch/finally
- 51Writing Generic Functions
- 52File Reading and Writing Basics
- 53Generating Random Numbers
- 54Bitwise Operators (AND, OR, XOR, shifts)
- 55Reading Command-Line Arguments
- 56Waiting for a Fixed Amount of Time (Thread.Sleep)
- 57Watch Out for Floating-Point Rounding Errors
- 58Reading from Standard Input
- 59FizzBuzz (the Classic Practice Problem)
- 60Checking Whether a Number Is Prime
- 61Set Operations with HashSet (Union, Intersection, Difference)
- 62Converting Number Bases (Binary, Hex)
- 63Checking Balanced Parentheses (an Application of Stacks)
- 64Checking Whether Two Words Are Anagrams
- 65Checking Whether a Year Is a Leap Year
- 66Converting Temperature (Celsius to Fahrenheit)
- 67Prime Factorization
- 68[Applied] Build a Simple Inventory Management Tool
Rounding Numbers (Floor, Ceiling, Round)
In this lesson you will learn how to round numbers in C# with Floor, Ceiling, and Round, and pick the right one for the job. This is for anyone searching for "C# Math.Round how to use".
Math.Floor() rounds down, Math.Ceiling() rounds up, and Math.Round() rounds to nearest (to even by default). "Shave it down", "push it up", and "go to whichever is closer" are useful mental labels.
The sample code shows how similar-looking decimals give different results depending on the method: Math.Floor(3.7) gives 3, Math.Ceiling(3.2) gives 4, and Math.Round(3.5) gives 4.
A common stumbling block for beginners is the slightly surprising default behaviour of Math.Round(). For monetary calculations it is worth checking the specification, and the MidpointRounding enum lets you control the tie-breaking rule precisely.
In real-world development, the choice changes your results - handling fractions in monetary calculations, lining up decimal places for display - so pick deliberately.
๐งช This site can't compile or run C# directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser โ nothing is sent anywhere).