CS 61BL Midterm Review

1
CS 61BL Midterm Review
2
Predict the output

• 1. What is the output of the following
  codeSystem.out.println ("ABCDEF".substring(0,4).
  substring (1,3))
• Option A Error
• Option B BCD
• Option C CD
• Option D BC

3
Predict the output

• 1. What is the output of the following
  codeSystem.out.println ("ABCDEF".substring(0,4).
  substring (1,3))
• Option A Error
• Option B BCD
• Option C CD
• Option D BC

• ABCDEF.substring(0,4) is the string ABCD
• ABCD.substring(1,3) is the string BC

4
What is the printed value of i after the
following code is executed ? public static void
main (String a)   int i 5  f
(i)  System.out.println("i" i) void f
(int i)  i i i

• Option A Error
• Option B i 0
• Option C i 5
• Option D i 25

5
What is the printed value of i after the
following code is executed ? public static void
main (String a)   int i 5  f
(i)  System.out.println("i" i) void
static f (int i)  i i i

• Option A Error
• Option B i 0
• Option C i 5
• Option D i 25

6
What is the value of s after the following code
is executed ?public static void main (String
a)   String s "A"  square (s) 
System.out.println("s " s) void static
square (String s)  s s s

• Option A Error
• Option B s
• Option C s A
• Option D s AA

7
What is the value of s after the following code
is executed ?public static void main (String
a)   String s "A"  square (s) 
System.out.println("s " s) void square
(String s)  s s s

• Option A Error
• Option B s
• Option C s A
• Option D s AA

8
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s1)

• Option A Error
• Option B true
• Option C false
• Option D ???

9
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s1)

• Option A Error
• Option B true
• Option C false
• Option D ???

10
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s2)

• Option A Error
• Option B true
• Option C false
• Option D ???

11
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s2)

• Option A Error
• Option B true
• Option C false
• Option D ???

12
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s3)

• Option A Error
• Option B true
• Option C false
• Option D ???

13
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s1 s3)

• Option A Error
• Option B true
• Option C false
• Option D ???

14
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s2 s3)

• Option A Error
• Option B true
• Option C false
• Option D ???

15
Predict the output String s0 nullString
s1 "A"String s2 new String ("A")String s3
s1 System.out.println(s2 s3)

• Option A Error
• Option B true
• Option C false
• Option D ???

16
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
j)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

17
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
j)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

18
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
i)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

19
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
i)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

20
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
k)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

21
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
k)

• Option A Error
• Option B 5
• Option C 7
• Option D 10

22
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
i.equals(k))

• Option A Error
• Option B 5
• Option C 7
• Option D 10

23
Predict the output int i 5int j
iint k ii 7j 10 System.out.println(
i.equals(k))

• Option A Error
• Option B 5
• Option C 7
• Option D 10

24
Dog is a subclass of Animal Animal a new
Animal()Dog d (Dog) a

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

25
Dog is a subclass of Animal Animal a new
Animal()Dog d (Dog) a

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

26
Dog is a subclass of Animal Animal a new
Dog()Dog d (Dog) a

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

27
Dog is a subclass of Animal Animal a new
Dog()Dog d (Dog) a

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

28
Dog is a subclass of Animal Animal aa new
Dog2

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

29
Dog is a subclass of Animal Animal aa new
Dog2

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

30
Dog is a subclass of Animal BOTH implement
eat( String food) Dog d new Dog()
((Animal) d).eat(kibble)

• Option A Does not compile
• Option B Run time error
• Option C Calls Dogs eat method
• Option D Calls Animals eat method

31
Dog is a subclass of Animal BOTH implement
eat( String food) Dog d new Dog()
((Animal) d).eat(kibble)

• Option A Does not compile
• Option B Run time error
• Option C Calls Dogs eat method
• Option D Calls Animals eat method

32
Dog is a subclass of Animal Animal aa new
Animal2 aa0 new Dog() aa1 new
Dog()Dog da (Dog ) aa

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

33
Dog is a subclass of Animal Animal aa new
Animal2 aa0 new Dog() aa1 new
Dog()Dog da (Dog ) aa

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

34
Dog is a subclass of Animal Animal aa new
Dog2 Dog da (Dog ) aa

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know

35
Dog is a subclass of Animal Animal aa new
Dog2 Dog da (Dog ) aa

• Option A Does not compile
• Option B Run time error
• Option C Works
• Option D Dont know