Default constructor
A default constructor is a constructor that can be invoked without caller-supplied arguments, whether explicitly declared or implicitly provided by a language or compiler.
100 C++ Mistakes and How to Avoid Them
A default constructor is a constructor that can initialize an object without requiring caller-supplied arguments.
- How it is used
- Uses default construction to clarify compiler-supplied members and to assess whether objects begin in a meaningful valid state.
- How deep it goes
- Explains generation rules, initialization consequences, invariant failures, and exception-based correction, stopping short of compiler implementation internals.
- Examples
- Uses Container declarations, Person initialization cases, arrays, vectors, setters, and validating constructors as concrete examples.
- What you can do after
- Evaluate whether default construction preserves valid state, then apply =default, =delete, required arguments, or constructor exceptions.
Read how 100 C++ Mistakes and How to Avoid Them explains default constructor →
Java Persistence with Spring Data and Hibernate epub
A no-arg constructor is a constructor that accepts no parameters and can create an instance without supplied arguments.
- How it is used
- Enables Hibernate and JPA to instantiate persistent classes and generate runtime proxies.
- How deep it goes
- Explains reflection, visibility, and proxy implications, but does not detail constructor invocation internals.
- Examples
- Uses User and Log entities with Lombok-generated no-argument constructors and explicit constructors accepting domain values.
- What you can do after
- Builds persistence-capable entities with framework-compatible constructors while retaining convenient application constructors.
Read how Java Persistence with Spring Data and Hibernate epub explains default constructor →
.NET in Action, Second Edition
A default constructor is a parameterless constructor supplied by the compiler or explicitly declared for a type.
- How it is used
- Explains how parameterless construction affects reflection, generic constraints, object initialization, and dependency injection.
- How deep it goes
- Distinguishes compiler-supplied, explicit, and optional-parameter constructors, but stops short of broader constructor rules.
- Examples
- Uses BasicStopwatch, ISystemClock, TestSystemClock, SystemClock, and Book to contrast injected and automatic construction.
- What you can do after
- Diagnose construction failures caused by missing parameterless constructors and choose explicit dependency injection when appropriate.
Read how .NET in Action, Second Edition explains default constructor →
Related concepts
- initializerkind of · An initializer is a function, declaration, or language construct that establishes the initial value or state of an object, value, computation, or process.
- Lombokproduced by · Lombok is a Java library that uses compile-time annotations to generate boilerplate code such as accessors, constructors, and object methods.
- invariantcontrasts with · An invariant is a property or condition that remains true across the valid states, operations, or specified transformations of a system or computation.
- constructor methodkind of · A constructor is a type-associated operation or callable that creates or initializes an instance and establishes its initial state.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.