| 24. 3. 1. Controlling scope with a variable declaration |
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By definition, the scope of a variable is a region of a program unit from which you can reference the variable. |
A variable is local to the block where it is declared. |
A variable is global to all sub-blocks of the block where it is declared. |
In the following code, variable V_STR1_main is local for the block labeled <> and global for the |
block labeled <>. Variable V_STR1_sub is visible only in the block <>. |
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SQL> <<MAIN>>
2 declare
3 v_str1_main VARCHAR2(10);
4 begin
5 v_str1_main :='ABC'; -- local
6 <<SUB>>
7 declare
8 v_str1_sub VARCHAR2(1);
9 begin
10 v_str1_main:='ABC'; -- local
11 v_str1_sub:='A'; -- global and visible
12 end;
13 v_str1_main :='ABC'; -- local
14 end;
15 /
PL/SQL procedure successfully completed.
SQL>
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