Return value
A return value is the result produced by a function, method, or operation and supplied to the code that invoked it.
Python How-To
The value produced by a function call, either explicitly by a return statement or implicitly when execution reaches the end of the function.
- How it is used
- Uses return values as the outputs of Python function calls that callers can assign and use.
- How deep it goes
- Works through explicit and implicit returns, None, tuple results, and unpacking, then gives guidance on how many values to return.
- Examples
- Contrasts sum with list.sort(), shows a function that appends but returns None, and calculates two statistics in one call.
- What you can do after
- Build it from scratch: define clear function outputs, unpack related results, and avoid chaining calls onto an unexpected None.
The Well-Grounded Rubyist, Fourth Edition
A return value is the value produced by evaluating a Ruby method call, implicitly taken from the method's last evaluated expression unless execution returns earlier.
- How it is used
- Connects method calls to expression values, object queries, and the results of iteration.
- How deep it goes
- Explains implicit and explicit returns, early exit, empty methods, multiple values, and the distinction between block results and method results.
- Examples
- Uses temperature conversion, ticket queries, irb iteration output, and a hand-built map accumulator.
- What you can do after
- Build it from scratch: implement a map-like method that collects block results and returns the resulting array.
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Learn AI-Assisted Python Programming, Second Edition
A return value is the result that a function sends back to the code that called it.
- How it is used
- Uses returned results to connect function calls, later computation, and testing.
- How deep it goes
- Explains calls, arguments, assignment, and test categories, but stops short of implementation internals.
- Examples
- Shows larger, money_made, max, input, and password-validation functions returning values.
- What you can do after
- Apply it via Python by capturing function results, inspecting outputs, and testing varied inputs.
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The Art of Unit Testing 3e
A return value is data produced by a function and delivered to its caller when the function completes.
- How it is used
- Uses return values as preferred observable exit points for value-based unit tests.
- How deep it goes
- Defines return values as observable exit points and contrasts them with state changes and third-party calls, treating them as testing boundaries.
- Examples
- Uses a number-summing function and a password verifier that returns booleans while calling an internal helper.
- What you can do after
- Evaluate/understand unit-test targets by asserting a function’s return value instead of its internal calls when possible.
The Quick Python Book, Fourth Edition
A return value is the result supplied by a function to its caller when the function completes execution.
- How it is used
- Uses returned results to pass computed data from functions to calling code and support refactoring into reusable functions.
- How deep it goes
- Explains explicit and implicit returns, early termination, discarded results, assignment, and name-collision failure, without covering implementation internals.
- Examples
- Demonstrates factorial computation, displayed versus assigned results, and text-cleaning functions used in a word-processing pipeline.
- What you can do after
- Apply it via Python functions to capture results, discard them deliberately, return early, and avoid callable-name collisions.
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The Well-Grounded Python Developer: How the pros use Python and Flask
A function return value is the object supplied by a function to the caller when the function completes.
- How it is used
- Defines function output as reusable data within API contracts and application-level function orchestration.
- How deep it goes
- Explains scalar results, compound tuples, implicit None, status flags, unpacking, reuse, and testability.
- Examples
- Uses abs, split_fullname tuple unpacking, and a full_name refactoring from printing to returning.
- What you can do after
- Apply it by returning reusable data, unpacking compound results, reporting operation status, and testing outputs directly.
Grokking Simplicity
The value produced as the result of a function invocation.
- How it is used
- Separates calculations from actions so callers can reuse results in the DOM, accounting, shipping, or further calculations.
- How deep it goes
- Defines explicit outputs, contrasts synchronous returns with asynchronous callbacks, and stops short of broader asynchronous abstractions.
- Examples
- Uses shopping-cart totals, DOM updates, shipping calculations, accounting reuse, and a synchronous-versus-asynchronous pet-count example.
- What you can do after
- Apply it to extract calculations, return reusable results, and replace asynchronous returns with callbacks.
Statistics Slam Dunk
A return value is the output produced by a function after it runs.
- How it is used
- Uses return values to explain how built-in and user-defined R functions produce usable analytical outputs.
- How deep it goes
- Defines return values and demonstrates explicit returns in custom functions, without descending into evaluation internals.
- Examples
- Demonstrates mean(), correlation conversion, and a Gini estimate with numeric outputs and a missing-argument error.
- What you can do after
- Build it from scratch by writing R functions that calculate, return, and reuse derived values.
Related concepts
- expressionproduced by · An expression is a syntactic construct in a programming language that evaluates to a value or designates an object, and may also cause side effects.
- last expressionproduced by · The last expression is the final expression evaluated in a Ruby method body, whose value becomes the method's implicit return value unless an explicit return intervenes.
- return statementconfigured by · A return statement ends the current function or routine invocation and optionally supplies its result to the caller.
- method callproduced by · A method call is an expression that invokes a method associated with an object, value, or type, optionally supplying arguments.
- functionproduced by · A function is a callable program unit that performs an operation, may accept inputs, and can produce a result or side effect.
- stored procedureproduced by · A stored procedure is a named executable routine stored in and invoked by a database management system to perform database operations.
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