Difference between revisions of "Block"

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A '''block''' is a sequence of [[Declaration|declarations]] followed by a sequence of [[Statement|statements]].
+
A '''block''' is a sequence of [[Declaration|declarations]] followed by a sequence of [[statement]]s.
 
The declarations are optional.
 
The declarations are optional.
 
The sequence of statements can be empty, but at least the [[Begin|<syntaxhighlight lang="pascal" enclose="none">begin</syntaxhighlight>]]…[[End|<syntaxhighlight lang="pascal" enclose="none">end</syntaxhighlight>]]-frame has to be present (in [[Routine|routines]] [[Asm|<syntaxhighlight lang="pascal" enclose="none">asm</syntaxhighlight>]]…<syntaxhighlight lang="pascal" enclose="none">end</syntaxhighlight> is allowed, too).
 
The sequence of statements can be empty, but at least the [[Begin|<syntaxhighlight lang="pascal" enclose="none">begin</syntaxhighlight>]]…[[End|<syntaxhighlight lang="pascal" enclose="none">end</syntaxhighlight>]]-frame has to be present (in [[Routine|routines]] [[Asm|<syntaxhighlight lang="pascal" enclose="none">asm</syntaxhighlight>]]…<syntaxhighlight lang="pascal" enclose="none">end</syntaxhighlight> is allowed, too).

Revision as of 00:05, 20 October 2019

Template:Translate A block is a sequence of declarations followed by a sequence of statements. The declarations are optional. The sequence of statements can be empty, but at least the beginend-frame has to be present (in routines asmend is allowed, too). The key feature of a block is, that declarations are only valid while the statements are processed. This concept is known as scope.

example

The following is a valid block:

const
	foobar = -1;
type
	booleanArray = array of boolean;
var
	check: booleanArray;
begin
	check := booleanArray.create(true, false, true);
end;

An indication, whether something constitutes a block, is, whether you can use it as part of a routine definition, as well as make a program out of it (syntactically; apart from the terminating dot).

see also