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Scope modifiers: Difference between revisions
Ada added
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Show the different scope modifiers available in your language and briefly explain how they change the scope of their variable or function. If your language has no scope modifiers, note it.
=={{header|Ada}}==
===Public and private declarative parts===
In [[Ada]] declarative region of a package has publicly visible and private parts. The private part is introduced by '''private''':
<lang ada>
package P is
... -- Declarations placed here are publicly visible
private
... -- These declarations are visible only to the children of P
end P;
</lang>
Correspondingly a type or object declaration may be incomplete in the public part providing an official interface. For example:
<lang ada>
package P is
type T is private; -- No components visible
procedure F (X : in out T); -- The only visible operation
N : constant T; -- A constant, which value is hidden
private
type T is record -- The implementation, visible to children only
Component : Integer;
end record;
procedure V (X : in out T); -- Operation used only by children
N : constant T := (Component => 0); -- Constant implementation
end P;
</lang>
===Bodies (invisible declarations)===
The keyword '''body''' applied to the packages, protected objects and tasks. It specifies an implementation of the corresponding entity invisible from anywhere else:
<lang ada>
package body P is
-- The implementation of P, invisible to anybody
procedure W (X : in out T); -- Operation used only internally
end P;
</lang>
===Private children===
The keyword '''private''' can be applied to the whole package, a child of another package:
<lang ada>
private package P.Q is
... -- Visible to the siblings only
private
... -- Visible to the children only
end P.Q;
</lang>
This package can be then used only by private siblings of the same parent P.
=={{header|Java}}==
<lang java>public //any class may access this member directly
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