Difference between revisions of "Block"
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− | A '''block''' is a sequence of [[Declaration|declarations]] followed by a sequence of [[ | + | 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 begin
…end
-frame has to be present (in routines asm
…end
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).