Wikibooks

C++ Language/Variables/Initialization

< C++ Language | Variables
C++ Language
  1. Overview
  2. Preprocessing
    1. Macros
    2. Tokenization
    3. Preprocessing Strings
    4. Compile-time Constants
    5. Compile-time Assertions
    6. Conditional-Compilation
  3. Namespace
    1. Namespace Shortcuts
    2. Nesting
    3. Splitting across Files
    4. Named and Unnamed
  4. Type
    1. Hungarian Prefixes
    2. Boolean
    3. Literals
    4. Bitwise Representation
    5. Max Value
    6. Conversion
    7. Enumeration
    8. Shortcuts
    9. Variant
    10. RTTI: RunTime Type Information
  5. Variables
    1. Lifetime and Scope
    2. Initialization
    3. Uniform Initialization
    4. Initialize without Constructor
    5. Decomposing-Auto
    6. Define at Same Time as Type
  6. Indirection
    1. Pointers
    2. Typed NULL
    3. Arrays
    4. Reference Variables
    5. Rvalue-References
    6. Smart Pointers
  7. Expressions
    1. Precedence
    2. Chain of Assignment
  8. Program Flow
    1. Loops
    2. The break Statement
    3. Return Value
    4. Parameters
    5. Function Overloading
    6. Function-Pointer
    7. Deprecating a Function
  9. Objects
    1. Accessibility
    2. Unwanted Compiler-Generated Functions
    3. Constructors
    4. Destructors
    5. Const Members
    6. Static Members
    7. Inheritance
    8. Operator Overloading
    9. Nested Classes
    10. Pointer to Members
    11. Low-Level C Structures
  10. Templates
    1. Templated-Functions
    2. Templated-Classes
    3. Templated-Variables
    4. Template-Parameters
    5. Traits
    6. Metaprogramming
    7. Concepts
  11. Error Handling
    1. Returning an Error Code
    2. Assertions
    3. C++ Exception Handling
  12. Standard Libraries
    1. C-Runtime
    2. STL: Standard Template Library
    3. Strings
    4. IOStreams
    5. Filesystem Access
    6. Multithreading
    7. RNG: Random Number Generator
  13. Obsolete Features

A constant variable (marked by the const keyword) must be initialized. If a static-lifetime variable is not manually initialized, then it will be automatically initialized to 0. If a local object variable is not manually initialized, then its default-constructor will construct it. If a local primitive variable is not manually initialized, then its value will be undefined until something gets assigned to it.

Additional information about initialization (includes interactive examples)

Retrieved from "https://en.wikibooks.org/w/index.php?title=C%2B%2B_Language/Variables/Initialization&oldid=4035352"