Initialization (programming): Difference between revisions

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===Initializer===

In C/C99/C++, an '''initializer''' is an optional part of a [[declarator (computing)|declarator]]. It consists of the '=' character followed by an [[expression (programming)|expression]] or a comma-separated list of expressions placed in curly brackets (braces). The latter list is sometimes called the "initializer list" or "initialization list" (although the term "initializer list" is formally reserved for initialization of class/struct members in C++; [[#Initializer list|see below]]).

A declaration which includescreates initializationa data object, instead of merely describing its existence, is commonly called a '''definition'''.

Many find it convenient to draw a distinction between the terms "declaration" and "definition", as in the commonly seen phrase "the distinction between a ''declaration'' and ''definition''...", implying that a declaration merely designates a data object (or function). In fact, according to the [[C++ standard]], a definition ''is'' a declaration. Still, the usage "declarations and definitions", although formally incorrect, is common.<ref>''C++ FAQs'', by Cline, Lomow, and Girou, Addison-Wesley, 1999, {{ISBN|0-201-30983-1}}.</ref> However, althoughAlthough all definitions counts as aare declarations, the opposite is not true. Allall declarations are not definitions.

C examples: