关于使用初始化块初始化变量的几种情况的运行结果分析

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1、用非静态初始化块初始化非静态变量

class TryInitialization
{
int[] values = new int[10];   //Static array member
//Initialization block
//static
{
  System.out.println("Running initialization block.");
  for (int i = 0; i < values.length; i++)
   values[i] = (int)(100.0 * Math.random());
}
//List values in the array for an object
void listValues()
{
  System.out.println();                //Start a new line
  for (int i = 0; i < values.length; i++)
   System.out.print(" " + values[i]); //Display values
  System.out.println();                //Start a new line
}
public static void main(String[] args)
{
  TryInitialization example1 = new TryInitialization();
  System.out.println("/nFirst object:");
  example1.listValues();
  TryInitialization example2 = new TryInitialization();
  System.out.println("/nSecond object:");
  example2.listValues();
  example1.listValues();
}
}

运行结果为：

Running initialization block.

First object:

24 59 34 10 6 46 92 50 54 0
Running initialization block.

Second object:

82 14 39 11 57 69 1 96 0 15

24 59 34 10 6 46 92 50 54 0

2、用静态初始化块初始化静态变量

即把

int[] values = new int[10];   //Static array member
//Initialization block
{
  System.out.println("Running initialization block.");
  for (int i = 0; i < values.length; i++)
   values[i] = (int)(100.0 * Math.random());
}
改成

static int[] values = new int[10];   //Static array member
//Initialization block
static
{
  System.out.println("Running initialization block.");
  for (int i = 0; i < values.length; i++)
   values[i] = (int)(100.0 * Math.random());
}

运行结果为：

Running initialization block.

First object:

41 29 51 25 84 1 70 18 47 23

Second object:

41 29 51 25 84 1 70 18 47 23

3、用非静态初始化块初始化静态变量

即改成

static int[] values = new int[10];   //Static array member
//Initialization block
  {
  System.out.println("Running initialization block.");
  for (int i = 0; i < values.length; i++)
   values[i] = (int)(100.0 * Math.random());
}

运行结果为

First object:

94 51 83 56 80 42 84 38 85 48
Running initialization block.

Second object:

51 30 58 13 11 76 98 23 42 34

4、用静态初始化块初始化非静态变量

即改成

int[] values = new int[10];   //Static array member
//Initialization block
static
{
  System.out.println("Running initialization block.");
  for (int i = 0; i < values.length; i++)
   values[i] = (int)(100.0 * Math.random());
}

编译错误

TryInitialization.java:9: non-static variable values cannot be referenced from a
static context
                for (int i = 0; i < values.length; i++)
                                    ^
TryInitialization.java:10: non-static variable values cannot be referenced from
a static context
                        values[i] = (int)(100.0 * Math.random());
                        ^
2 errors