有下面的代码: Integer time = 12;
Double lateTime = 12.30;
Boolean late = false;
Double result = late ? lateTime : time; //Why here can I assign an Integer to a Double?
System.out.println(result);
它打印:
说我有延伸AnyVal并使用Long内部的自定义类: case class Instruction(underlying: Long) extends AnyVal
当我添加Instruction s到这是专门为Long集合,做了Instruction的需要拳击? (是否有Scala集合而专门为Long?我需要一个索引序列。)
请帮助我理解这一段代码在科特林文档: - val a: Int = 10000
print(a === a) // Prints 'true'
val boxedA: Int? = a
val anotherBoxedA: Int? = a
print(boxedA === anotherBoxedA) // !!!Prints 'false'!!!
现在,我明白,第一个int a =
在自动装箱常数int和short类型到Byte没有错误,但与long类型有常量错误。为什么? final int i = 3;
Byte b = i; // no error
final short s = 3;
Byte b = s; // no error
final long l = 3;
Byte b = l; // error
我有一个方法 public double getNumberOfBooks(final int count, final double Price,
final Long Quantity, final double totalValue)
现在下面 public void testgetNumberOfBooks()
{
Long obj = Long.valueOf