GOTO statement in C#.NET
try
{...
block:
....
}
catch{ ..}
GOTO block
...
....
finally{...}
Will goto 开发者_运维百科executes in this case??
It won't compile because of 'GOTO block
' instead of 'goto block;
' and even if it was right it won't compile because C# specifications states (§8.9.3):
The target of a
goto
identifier statement is the labeled statement with the given label. If a label with the given name does not exist in the current function member, or if the goto statement is not within the scope of the label, a compile-time error occurs. This rule permits the use of a goto statement to transfer control out of a nested scope, but not into a nested scope.
Also I found couple specs interesting for me too:
A goto statement cannot exit a
finally
block (§8.10). When a goto statement occurs within afinally
block, the target of the goto statement must be within the samefinally
block, or otherwise a compile-time error occurs.
And:
A goto statement is executed as follows:
- If the goto statement exits one or more try blocks with associated finally blocks, >control is initially transferred to the finally block of the innermost try statement. When >and if control reaches the end point of a finally block, control is transferred to the >finally block of the next enclosing try statement. This process is repeated until the >finally blocks of all intervening try statements have been executed.
- Control is transferred to the target of the goto statement.
the latter means that if you have
try
{
...
goto Label1;
}
finally
{
CloseAll();
}
Label1:
MethodB();
it will call CloseAll()
before actually transferring control to the Label1
and executing MethodB()
.
Makes perfect sense, but I never thought about it...
No. block: label must be outside the try in order for the goto to see it. The code won't even compile. Are you taking a test :)?
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