- 01Getting Started
- 02Your First Output (puts)
- 03Working with Variables
- 04Conditionals (if statements)
- 05Loops
- 06Writing a Method (Function)
- 07Working with Arrays
- 08Loops (while statements)
- 09Classes (Object-Oriented Programming)
- 10Error Handling (begin...rescue)
- 11Handy Array Methods
- 12Recursive Functions
- 13Using the Standard Library
- 14The case/when Statement
- 15The Ternary Operator
- 16Inheritance (Extending a Class)
- 17Writing Comments
- 18Logical Operators (AND, OR, NOT)
- 19Constants (names starting with a capital)
- 20Splitting and Joining Strings (split, join)
- 21Writing nil-Safe Code
- 22Searching an Array (include?)
- 23Transforming an Array (map)
- 24Two-Dimensional Arrays (Tabular Data)
- 25Writing a Custom Exception Class
- 26Default Parameter Values
- 27Working with Set
- 28Testing with Your Own assert Method
- 29Higher-Order Functions (Passing a Block)
- 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 (strip, Unifying Case)
- 40Shallow Copy vs. Deep Copy
- 41Enum Basics
- 42Flattening an Array
- 43Reversing a String and Checking for Palindromes
- 44Pairing Up Two Arrays (the zip operation)
- 45Rounding Numbers (floor, ceil, round)
- 46Multi-Line Strings (Heredoc)
- 47Methods That Return Multiple Values
- 48Finding the GCD and LCM
- 49Formatting Numbers (Padding Digits, Decimal Places)
- 50Cleanup Logic with begin/rescue/ensure
- 51Methods That Work with Any Type
- 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 (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 Set (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
Loops
In this lesson you will learn to repeat work with Ruby's each method, and get a feel for idiomatic Ruby looping. This is for anyone searching for "Ruby each how to use" or "Ruby loops".
Writing (range).each do |variable| ... end repeats work. The pairing of the each method with a block is a very important basic pattern that appears everywhere in Ruby code.
The sample code uses (1..5).each do |i| to take the numbers 1 through 5 one at a time and print a message. The part enclosed in do ... end is called a "block" - a chunk of work handed to the each method.
A common stumbling block for beginners is looking for a for statement like the one they know from other languages. Ruby does have for, but each with a block is the more common and more natural style, and that shift in thinking takes a moment.
The |i| part is the "block parameter", where each value taken from the range arrives. This each-plus-block pattern reappears in many methods you will meet later, such as map and select.
๐งช This site can't compile or run Ruby 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).