Slide 24
Slide 24 text
pattern match
• Option ͷ matching Ͱཏ͞Εͯͳ͍߹ܯࠂ
• ΦϒδΣΫτΛղͯ͠ΛऔΓग़͢͜ͱ͕Ͱ͖Δ
findById(id)
match
{
case
Some(user)
if
user.isAdmin
=>
“administrator”
case
Some(user)
=>
“normal
user”
//
case
_
=>
“guest
user”
warning!
}
val
r
=
“""(\d{4})-‐(\d{2})-‐(\d{2})""".r
“2015-‐02-‐22”
match
{
case
r(year,
month,
day)
=>
something(year,
month,
day)
case
_
=>
throw
new
Exception(“format
exception”)
}
if Ψʔυઅ͕͋Δ
߹ବ