Block
A code block is a grouped region of code treated as a unit, with boundaries and scope or execution behavior determined by its language or context.
The Well-Grounded Rubyist, Fourth Edition
A block is a fragment of Ruby code supplied with a method call that the method can execute.
- How it is used
- Uses blocks to supply executable behavior to method calls, especially iterators and scoped operations.
- How deep it goes
- Explains yielding, parameters, return values, scope, precedence, and proc conversion through small implementations and contrasts.
- Examples
- Builds homemade loop, times, and map methods and contrasts block-based file access with an explicit read loop.
- What you can do after
- Build it from scratch in simple iterators, then apply it to collection processing and scoped file access.
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Get Programming: Learn to code with Python
- How it is used
- Uses indented code blocks to control which statements run when an if condition is true.
- How deep it goes
- Explains indentation, conditional execution, and nested blocks, but does not treat blocks beyond conditional statements.
- Examples
- Uses positive, negative, and zero checks, plus nested decisions about hunger and chocolate prices.
- What you can do after
- Apply Python if statements to write, test, and debug programs that make decisions.
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The Quick Python Book, Fourth Edition
A code block is a sequence of one or more statements grouped as a syntactic unit and executed under a common control structure.
- How it is used
- Structures loop bodies, conditional clauses, and other compound statements through indentation.
- How deep it goes
- Defines block membership, nesting, single-line cases, and indentation errors, but does not discuss interpreter internals.
- Examples
- Uses factorial calculation, conditional assignment, nested interactive blocks, and examples of unexpected or mismatched indentation.
- What you can do after
- Apply indentation to write nested control-flow bodies and diagnose common indentation errors.
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Learn Rust in a Month of Lunches
A code block is a delimited sequence of Rust statements and expressions that forms a lexical scope and produces a value.
- How it is used
- Introduces lexical scope, variable lifetimes, and expression values while teaching Rust's first declarations and functions.
- How deep it goes
- Defines scope and return behavior through small examples, then stops short of deeper ownership or lifetime analysis.
- Examples
- Uses nested numeric blocks, out-of-scope variables, arithmetic block values, and functions returning integers.
- What you can do after
- Apply code blocks to limit variable scope and compute values, using compiler feedback to correct semicolon and lifetime mistakes.
Modern C, Third Edition
A block is a grammatical structure that groups declarations and statements within a delimited program region.
- How it is used
- Organizes declarations and statements into nested grammatical regions whose boundaries determine identifier visibility.
- How deep it goes
- Defines block grammar, distinguishes primary and secondary blocks, and traces four nested scope levels without descending into implementation mechanics.
- Examples
- Uses main, its parameter list and body, and a for loop with a nested loop body.
- What you can do after
- Evaluate/understand identifier visibility by locating declaration points and enclosing blocks.
Related concepts
- map!used by · map! is a mutating collection operation that applies a transformation to elements and writes the resulting values into a destination collection.
- iteratorused by · An iterator is an object or abstraction that provides successive values from a sequence or data source through a traversal protocol.
- indentationconfigured by · Indentation is leading whitespace or spacing that positions content relative to its surrounding area and can represent hierarchy or structural nesting.
- conditional logichas part · Conditional logic is a programming technique that selects execution paths, actions, or result values according to evaluated conditions.
- scopeconfigures · Scope is the region of a program in which names are visible and can be resolved according to the language’s lookup rules.
- looppart of · A loop is a programming control-flow construct that repeatedly executes a block of instructions according to an iteration rule or continuation condition.
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