Ruby types, symbols, strings, arrays, hashes, blocks, procs, classes, modules and mixins.
39 cards · basic cards · AI-written, checked twice. Edit anything.
- What are the main primitive data types in Ruby?
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Integer, Float, String, Symbol, Boolean (true/false), and nil- How do you create a symbol in Ruby?
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Precede an identifier with a colon: :symbol_name- What is the key difference between a symbol and a string?
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Symbols are immutable and reused in memory; strings are mutable and create new objects each time- How do you interpolate a variable into a double-quoted string in Ruby?
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Wrap the variable in #{}: "Hello, #{name}"- What does the .to_s method do?
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Converts an object to its string representation- How do you create an array in Ruby?
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Use square brackets: [1, 2, 3] or call Array.new- How do you access the first element of an array?
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Use index 0 or call .first: array[0] or array.first- How do you access the last element of an array?
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Use index -1 or call .last: array[-1] or array.last- How do you add an element to the end of an array?
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Use .push or the << operator: array.push(x) or array << x- What does the .pop method do to an array?
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Removes and returns the last element- What is the key difference between an array and a hash?
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Arrays use numeric indices (0, 1, 2, ...); hashes use any object as a key- How do you create a hash in Ruby?
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Use curly braces with key-value pairs: {key: value} or {"key" => value}- How do you access a value in a hash?
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Use square brackets with the key: hash[:key]- Are symbols commonly used as hash keys?
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Yes, symbols are the standard choice: {name: "John", age: 30}- What does the .each method do?
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Iterates over each element in a collection and runs a block for each
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