Difference between revisions of "Block"
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A '''block''' is a sequence of [[Declaration|declarations]] followed by a sequence of [[statement]]s. | A '''block''' is a sequence of [[Declaration|declarations]] followed by a sequence of [[statement]]s. | ||
The declarations are optional. | The declarations are optional. | ||
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This concept is known as [[Scope|scope]]. | This concept is known as [[Scope|scope]]. | ||
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The following is a valid block: | The following is a valid block: | ||
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<syntaxhighlight lang="pascal"> | <syntaxhighlight lang="pascal"> | ||
const | const | ||
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end; | end; | ||
</syntaxhighlight> | </syntaxhighlight> | ||
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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|<syntaxhighlight lang="pascal" enclose="none">program</syntaxhighlight>]] out of it (syntactically; apart from the terminating dot). | 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|<syntaxhighlight lang="pascal" enclose="none">program</syntaxhighlight>]] out of it (syntactically; apart from the terminating dot). | ||
== see also == | == see also == | ||
* [[Comments#block comments|block comments]] | * [[Comments#block comments|block comments]] | ||
Revision as of 07:11, 27 December 2019
│ English (en) │
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).
