Java Multiple Choice Questions & Answers on ActionEvent & AdjustmentEvent Class for Freshers

1. Which of these events is generated when a button is pressed?

a) ActionEvent
b) KeyEvent
c) WindowEvent
d) AdjustmentEvent

Answer: a

Explanation: Action event is generated when a button is pressed, a list item is double-clicked or a menu item is selected.

2. What is an event in delegation event model used by Java programming language?

a) An event is an object that describes a state change in a source.
b) An event is an object that describes a state change in processing.
c) An event is an object that describes any change by the user and system.
d) An event is a class used for defining object, to create events.

Answer: a

Explanation: An event is an object that describes a state change in a source.

3. Which of these methods can be used to obtain the command name for invoking ActionEvent object?

a) getCommand()
b) getActionCommand()
c) getActionEvent()
d) getActionEventCommand()

Answer: b

4. Which of these are integer constants defined in ActionEvent class?

a) ALT_MASK
b) CTRL_MASK
c) SHIFT_MASK
d) All of the mentioned

Answer: d

Explanation: Action event defines 4 integer constants ALT_MASK, CTRL_MASK, SHIFT_MASK and ACTION_PERFORMED

5. Which of these methods can be used to know which key is pressed?

a) getKey()
b) getModifier()
c) getActionKey()
d) getActionEvent()

Answer: b

Explanation: The getModifiers() methods returns a value that indicates which modifiers keys (ALT, CTRL, META, SHIFT) were pressed when the event was generated.

6. Which of these events is generated by scroll bar?

a) ActionEvent
b) KeyEvent
c) WindowEvent
d) AdjustmentEvent

Answer: d

7. Which of these methods can be used to determine the type of adjustment event?

a) getType()
b) getEventType()
c) getAdjustmentType()
d) getEventObjectType()

Answer: c

8. Which of these methods can be used to know the degree of adjustment made by the user?

a) getValue()
b) getAdjustmentType()
c) getAdjustmentValue()
d) getAdjustmentAmount()

Answer: a

Explanation: The amount of the adjustment can be obtained from the getvalue() method, it returns an integer value corresponding to the amount of adjustment made.

9. Which of these events will be notified if scroll bar is manipulated?

a) ActionEvent
b) ComponentEvent
c) AdjustmentEvent
d) WindowEvent

Answer: c

Explanation: AdjustmentEvent is generated when a scroll bar is manipulated.

10. Which of these constant value will change when the button at the end of scroll bar was clicked to increase its value?

a) BLOCK_DECREMENT
b) BLOCK_INCREMENT
c) UNIT_DECREMENT
d) UNIT_INCREMENT

Answer: d

Explanation: UNIT_INCREMENT VALUE will change when the button at the end of scroll bar was clicked to increase its value.