case — Jump label that starts a branch within a switch block.
case( : : Constant : )
case defines a jump label within a switch block.
It starts a branch that is executed if the value of the control expression
of the switch statement matches the constant integer expression
that is defined in Constant.
For this parameter only constant integer expressions are accepted.
Variable expressions and other data types are not allowed.
As in the programming languages C, C++, and C# the case statement
does not open a block that is automatically left at the next case
or default statement.
In contrast, it works just like a goto label that is accessed if the label
matches.
In order to leave a case branch and continue execution after the
end of the switch block, the break statement can be used
anywhere within the switch block.
Constant (input_control) integer → (integer)
Constant integer expressions that determines for which value of the switch control expression the branch is accessed.
默认值： 1
case (as an operator) always returns 2 (
H_MSG_TRUE)
.
switch,
default,
endswitch,
if
Foundation