5.tostring()产生字符串“5”，intersect输出两个字符串中都存在的字符 a.func(b) 等价于 a func b...
(classOf[MySubClassOfMySuperClass], ...)); 顺便说一句,令人困惑的诊断是因为生成java.lang.Class实例的classOf不是一个可以像函数一样调用的值或方法(“不带参数”)。请记住,Scala 始终会尝试将类型参数推断为泛型,例如classOf,奇怪的是,在没有任何类型参数的情况下使用时,它会成功地完成此操作。它推断类型...
scala>valarr=newArrayBuffer[Int]<console>:11:error:notfound:typeArrayBuffervalarr=newArrayBuffer[Int]^// 变长数组需要手动引入scala>importscala.collection.mutable.ArrayBufferimportscala.collection.mutable.ArrayBufferscala>valarr=newArrayBuffer[Int]arr:scala.collection.mutable.ArrayBuffer[Int]=ArrayBuffer()//...
scala>val arr=newArrayBuffer[Int]<console>:11:error:not found:typeArrayBufferval arr=newArrayBuffer[Int]^// 变长数组需要手动引入scala>importscala.collection.mutable.ArrayBufferimportscala.collection.mutable.ArrayBufferscala>val arr=newArrayBuffer[Int]arr:scala.collection.mutable.ArrayBuffer[Int]=ArrayBuffer...
This script starts with a variable definition,vari=0. Type inference givesithe typescala.Int, because that is the type of its initial value,0. Thewhileconstruct on the next line causes theblock(the code between the curly braces) to be repeatedly executed until the boolean expressioni<args.le...
res0: Boolean = false “asInstanceOf” method is used to cast the object to the given a type. If the given object and type are of same type, then it cast to given type. Otherwise, it throws java.lang.ClassCastException. scala> val str = "Hello".asInstanceOf[String] ...
def signsAreOpposite(x: Double, y: Double):Boolean = { if (x < 0 && y > 0) return true else if (x > 0 && y < 0) return true else return false } } My intent in this tutorial is to demonstrate Scalafunctionsandfunction literals, but if you're interested in how this algorithm...
@SethTisue: "In Scala through 2.12, .iterator has no parameter lists and the compiler says 'Iterator[...] does not take parameters' if you write .iterator(). So somebody made a different decision on this years ago. Just leaving it like it was doesn't feel terrible to me. Even if yo...
Checks for if statements where the condition is always true or false. Not only checks for the boolean literals, but also any expression that the compiler is able to turn into a constant value. Eg,if (0 < 1) then else that Checks for a format string that is not invalid, such as inval...
<console>:12: warning: match may not be exhaustive. It would fail on the following input: false bool match { ^ Got heads scala.MatchError: false (of class java.lang.Boolean) at .<init>(<console>:11) at .<clinit>(<console>) ......