Wrong question 0913

subclass a inherits the parent Class B, a A = new A (), the parent Class B constructor, the parent class B static code block, the parent class B non-static code block, the subclass a constructor, the subclass a static code block, the subclass a non-static code block execution order is?

A; parent class B static code block, parent Class B constructor, subclass a static code block, parent class B non-static code block, subclass a constructor, subclass a non-static code block

B: Parent class B Static code block, parent Class B constructor, parent class B non-static code block, subclass a static code block, subclass a constructor, subclass a non-static code block

C; parent Class B static code block, subclass a static code block, parent class B non-static code block, parent Class B constructor, subclass a non-static code block, sub-Class A constructor

D; parent Class B constructor, parent class B static code block, parent class B non-static code block, subclass a static code block, subclass a constructor, subclass a non-static code block
Answer: C.

In class design, the member variables of a class are required to be accessed only by classes under the same package, which of the following modifiers should be used ()

a;protected

B;public

C:private

D: no modifiers required

Analytical:

The following is about the JVM memory, what is the wrong word?

A: The program counter is a small area of memory that indicates the byte code executed by the current thread executes to the first line, which is thread-isolated

The B:java method executes the memory model for storing local variables, operand stacks, dynamic links, method exits and other information, which is thread-isolated

C: The method area is used to store JVM-loaded class information, constants, static variables, and even data such as compiler-compiled code, which are thread-isolated

D: In principle, all objects allocate memory on the heap, which is shared between threads
Answer: C

Analytical:

String str = "Hello world" in Java the following statement is wrong?

a:str+= '  a '

B:int strlen = str.length

c:str=100

d:str=str+100
Analytical:

Analytical:

Wrong question 0913