++在后：先赋值再自身加1
++在前：先自身加1再赋值

1.What is i printed? A

public class Test {public static void main(String[] args) {int j = 0;int i = ++j + j * 5;System.out.println("What is i? " + i);}}

A.6
B.1
C.0
D.5

2.What is y displayed in the following code?D

public class Test {public static void main(String[] args) {int x = 1;int y = x++ + x;System.out.println("y is " + y);}}

A.y is 2.
B.y is 1.
C.y is 4.
D.y is 3.

3.What is i printed in the following code?C

public class Test {public static void main(String[] args) {int j = 0;int i = j++ + j * 5;System.out.println("What is i? " + i);}}

A.0
B.6
C.5
D.1

4.What is y displayed?B

public class Test {public static void main(String[] args) {int x = 1;int y = x + x++;System.out.println("y is " + y);}}

A.y is 3.
B.y is 2.
C.y is 4.
D.y is 1.