0 じゃないとだめなのか 0.0でやるか？
as Doubleいるかどうか。
let a: Double = 0
if a == 0 {
print("== 0")
} else {
print("== 0じゃない")
}
if a == 0 as Double {
print("== 0 as Double")
} else {
print("== 0 as Doubleじゃない")
}
if a == 0.0 {
print("== 0.0")
} else {
print("== 0.0じゃない")
}
if a == 0.0 as Double {
print("== 0.0 as Double")
} else {
print("== 0.0 as Doubleじゃない")
}
let defaultsKey = "defaultsKey"
let defaults = UserDefaults.standard
let doubleValue = defaults.double(forKey: defaultsKey)
switch doubleValue {
case 0:
print("case 0")
default:
print("case 0じゃない")
}
switch doubleValue {
case 0.0:
print("case 0.0")
default:
print("case 0.0じゃない")
}
switch doubleValue {
case 0 as Double: // ここは警告出た
print("case 0 as Double")
default:
print("case 0 as Doubleじゃない")
}
switch doubleValue {
case 0.0 as Double: // ここは警告出た
print("case 0.0 as Double")
default:
print("case 0.0 as Doubleじゃない")
}
警告はこれの事
'as' test is always true
結果ログ
["== 0"] ["== 0 as Double"] ["== 0.0"] ["== 0.0 as Double"] ["case 0"] ["case 0.0"] ["case 0 as Double"] ["case 0.0 as Double"]
