Block (programming): Difference between revisions

Revision as of 20:27, 12 November 2017

Revision as of 20:27, 12 November 2017

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{{Programming paradigms}}

In [[computer programming]], a '''block''' or '''code block''' is a lexical structure of [[source code]] which is grouped together. Blocks consist of one or more [[Declaration (computer programming)|declarations]] and [[statementStatement (programmingcomputer science)|statements]]. A programming language that permits the creation of blocks, including blocks nested within other blocks, is called a '''block-structured programming language'''. Blocks are fundamental to [[structured programming]], where [[control structure]]s are formed from blocks.

The function of blocks in programming is to enable groups of statements to be treated as if they were one statement, and to narrow the [[lexical scope]] of variables, procedures and functions declared in a block so that they do not conflict with variables having the same name used elsewhere in a program for different purposes. In a block-structured programming language, the names of variables and other objects such as procedures which are declared in outer blocks are visible inside other inner blocks, unless they are [[Variable shadowing|shadowed]] by an object of the same name.