[swift-users] while case and if case usage

[Ramakrishna Mallireddy]

I am not sure if this helps, This is how I understand it.

what happens when you use normal switch.

switch someEnumExpression {
 case someEnum.Element1: execute block / statements
 default: executeDefault
}

// it checks each case with someEnumExpression, and if true then run it,
may be actual implementation might use dictionary with someEnum as Key
if case someEnum.Element1 == someEnumExpression {
  execute block / statements
} else {
  executeDefault
}

unroll your switch to if's, then I am sure you will understand its
construct...but why swift provide this control branch statements with case,
because at time I am sure that or only want to check an expression is of
particular enum case, then I use the if case like above. while is similar.

I am sorry if my explanation is vague.


On Wed, Feb 24, 2016 at 10:49 AM, Thomas# Chiang via swift-users <
swift-users at swift.org> wrote:

> have any document explain about "while case" and "if case" ? thank you ~
>
> TMS#
>
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