*Once per 
    1. Static variable declaration
    2. Static block
*Once per object
    3. variable declaration
    4. initialization block
    5. constructor

但是根据这段代码我显然是错误的：

class SomethingWrongWithMe
    {
        {
            b=0;         //no. no error here.
            int a = b;   //Error: Cannot reference a field before it is defined.
        }
        int b = 0;
    }

如果我这样做,错误会消失：

class SomethingWrongWithMe
    {
        int b = 0;
        {
            b=0;
            int a = b;   //The error is gone.
        }
    }

我不知道为什么不会有错误

b=0;