如何重新计算变量？

Question

我正在考虑每次调用/使用它们时都计算一个变量？这可能吗？

int myvalue = rn.nextInt(100 - 1 + 1) + 1;
System.out.println("call myvalue: " + myvalue);
System.out.println("call myvalue again: " + myvalue);
System.out.println("call myvalue the third time: " + myvalue);

Answer 1

方案一，创建方法：

static int myvalue(Random rn) {
    return rn.nextInt(100 - 1 + 1) + 1;
}

System.out.println("call myvalue: " + myvalue(rn));
System.out.println("call myvalue again: " + myvalue(rn));
System.out.println("call myvalue the third time: " + myvalue(rn));

选项 2，使用 lambda 表达式(Java 8+)：

IntSupplier myvalue = () -> rn.nextInt(100 - 1 + 1) + 1;
System.out.println("call myvalue: " + myvalue.getAsInt());
System.out.println("call myvalue again: " + myvalue.getAsInt());
System.out.println("call myvalue the third time: " + myvalue.getAsInt());

Answer 2

创建一个返回 int 的方法，如下所示：

static int myvalue()
{ 
    Random rn= new Random();  
    return rn.nextInt(100 - 1 + 1) + 1;
}

并在System.out.println()中调用它：

public static void main(String[] args) 
{                       
  System.out.println("call myvalue: " + myvalue());
  System.out.println("call myvalue again: " + myvalue()); 
  System.out.println("call myvalue the third time: " + myvalue());
}