我相信你一直在那里.你想说“如果flib这样做,如果flob这样做,如果松弛做饮食等”,其中任何数量都可以是真的,那么最后你想要一个“如果你没有做任何一个”.
例如(下面的例子是在Swift中,因为我一直在玩它,但我认为大多数语言的情况都是一样的):
let thing = 101
var isInteresting = false
if (thing % 3 == 0) {
println("\"\(thing)\" is a multiple of three.")
isInteresting = true
}
if (thing > 100) {
println("\"\(thing)\" is greater than one hundred.")
isInteresting = true
}
if (thing > 1000) {
println("\"\(thing)\" is greater than one thousand.")
isInteresting = true
}
if !isInteresting {
println("\"\(thing)\" is boring.")
}
我发现跟踪一个布尔值告诉我是否做了什么或者没有笨拙.
我想出的唯一另一种方式是:
let thing = 101
let isAMultipleOfThree = (thing % 3 == 0)
let isGreaterThan100 = (thing > 100)
let isGreaterThan1000 = (thing > 1000)
if isAMultipleOfThree {
println("\"\(thing)\" is a multiple of three.")
}
if isGreaterThan100 {
println("\"\(thing)\" is greater than one hundred.")
}
if isGreaterThan1000 {
println("\"\(thing)\" is greater than one thousand.")
}
if !(isAMultipleOfThree || isGreaterThan100 || isGreaterThan1000 ) {
println("\"\(thing)\" is boring.")
}
但如果有什么更糟糕的话(如果你添加一个新的条款,你需要记住在三个地方添加它.
所以我的问题是,有一种简洁,简洁的方法吗?
我梦想着一个虚构的开关式声明:
switchif { //Would have fallthrough where every case condition is checked
case thing % 3 == 0:
println("\"\(thing)\" is a multiple of three.")
case thing >100 :
println("\"\(thing)\" is greater than one hundred.")
case thing > 1000:
println("\"\(thing)\" is greater than one thousand.")
none: //Unlike 'default' this would only occur if none of the above did
println("\"\(thing)\" is boring.")
}
最佳答案 这是一个没有完美答案的好问题.但是,除了你建议的那些之外,还有另外一个想法:在一个过程中封装测试机器,以使调用代码至少更加简化.
具体来说,对于您的示例,调用代码可以是:
if (! doInterestingStuff(101)) {
println("\"\(thing)\" is boring.");
}
如果测试被封装到一个过程中:
public boolean doInterestingStuff(int thing) {
var isInteresting = false
if (thing % 3 == 0) {
println("\"\(thing)\" is a multiple of three.")
isInteresting = true
}
if (thing > 100) {
println("\"\(thing)\" is greater than one hundred.")
isInteresting = true
}
if (thing > 1000) {
println("\"\(thing)\" is greater than one thousand.")
isInteresting = true
}
return isInteresting
}