CECS 174 EXAMINATION #2 SAMPLE
Multiple choice
1.. Which of the following is a relational operator?
a. =
b. ==
c. !
d. &&
Answer: b
3. Which of the following is not a logical operator?
a. !
b. ||
c. !=
d. &&
Answer: d
4. Suppose x is 5 and y is 7. What is the value of the following expression?
(x != 7) && (x <= y)
a. false
b. true
c. This is an invalid expression in C++
d. None of these
Answer: b
5. Suppose that x is an int variable. Which of the following expression
always evaluates to true?
a. (x > 0) || ( x <= 0)
b. (x > 0) || (x == 0)
c. (x > 0) && ( x <= 0)
d. (x > 0) && (x == 0)
Answer: a
6. What is the output of the following C++ code?
x = 0;
if(x < 0)
System.out.prinntln("One ");
System.out.prinntln("Two ");
System.out.prinntln("Three");
a. Two
b. Two Three
c. One Two Three
d. None of these
Answer: b
7. After the execution of the following code, what is the value of sum?
sum = 0;
num = 10;
if(num > 0)
sum = sum + 10;
else
if(num > 5)
sum = num + 15;
a. 0
b. 10
c. 20
d. 25
Answer: b
8. What is the output of the following code fragment?
x = 10;
if(x > 15)
x = 0;
System.out.println(x);
else
System.out.println(x+5);
a. 0
b. 5
c. 10
d. None of these
Answer: d
Part II
1. Circle 0 if the expression evaluates to 0 (false), or 1 (true) if the
expression evaluates to 1 (true).
Answers in bold
int count = 0, limit = 10;
0 1 1. ! (count = = 12)
0 1 2. ( 5 && 7) + (!6)
0 1 3. !( ((count < 10 ) | | (x < y)) && (count > = 0) )
0 1 4. (limit < 20) | | (limit/count) > 7)
0 1 5. !count
2. Circle 0 if the expression evaluates to 0 (false), or 1 (true) if the
expression evaluates to 1 (true).
[ 1/2 point each; 5 points total] Answers in bold and underline
int x = 2, y = 3;
0 1 1. x = = y 0 1 6. x >= y
0 1 2. x && (y < 10) 0 1 7. !x || (y < 10)
0 1 3. !5 0 1 8. x < 10 && y > -10
0 1 4. x != y 0 1 9. x - 2
0 1 5. x < 0 && y < 9 || x > 0 0 1 10. !(!5)
3. Assuming X is 7, and Y is 12, indicate by circling the T or F if each of the following relational expressions is true or false:
a. X = = 5 T F
b. 7 <= (X + 2) T F
c. 2 * X < Y T F
d. Y + 3 ! = X T F
4. For each expression, find values for x and y that makes it true.
a. x > 10 || y ! = 5
Answer: x is 20 and y is 6
b. x > 10 && y < x + 4
Answer: x is 11 and y is 0
5. Rewrite the following part of the program that it uses only one if statement. If it is not possible to rewrite it using only one if, explain why. [ 2 points]
if ( x > 12)
Answer
if ( x < 100)
System.out.println("Number is in range");
if ( x > 12 && x < 100 )
System.out.println("Number is in range");
6. Write Java statements that will
a. display x>y if x is greater than y and display y>=x otherwise.
Answer : if (x > y)
cout<<"x>y"<<endl;
else
cout<<"y>=x"<<endl;
7. Write a Java expression that determines x is greater than10 and less than 20?
Answer 10 < x && x < 20
8. Write a Java expression that determines num is less than 0 or num is greater than 50
Answer num < 10 || num > 50
9. What value will the variable x has after executing
x =6;
if ( k < 10)
if (k < 5)
x =7;
else
x = 8;
if k has the value
a. 9
Answer: 8
b. -2
Answer: 7
10. Consider the following section of a program:
if ( x > y )
if (z > 100)
x = y;
else
y = z;
else
if ( z <= 100)
y = x;
else
z = y;
System.out.println(" x + " " + y + " " + z);
What is displayed when x = 10, y = 20, and z = 75?
Answer: 10 10 75
What is displayed when x = 20, y = 10, and z = 75?
Answer 20 75 75
11. Which of the following correctly lists the sequence of statements that Java executes, given the code fragment: [ 2 points]
a. 1,2,3,4,5 b. 1,2,5 c. 1,2,4,5 d. 1,2,3,5 e. none of these above
Answer (Select a, b,c,d or e)
c
12. Given the following code snippet:
int myInt = 3;
if (myInt < 5)
if (myInt < 3)
System.out.println(< 3);
else
if (myInt > 2)
System.out.println(>2);
else
System.out.println(Other);
What will appear in the standard output? [ 3 points ]
Answer: >2
13. [6 points] Write a Java statement which displays the following pattern on
the screen.
******
******
******
******
Your solution must meet the following requirements:
- Can not use more than one statement System.out.println()
- Can not use more than one statement System.out.print("*")
- Can not use more than two for loops
Answer
int a=4,b=6;
for(int i=0;i<a;i++)
{ for(int j=0;j < b;j++)
System.out.print("*");
System.out.println();
14. Write a program that is using loop statements to display an output below. [5
points]
1
12
123
1234
12345
123456
1234567
12345678
123456789
12345678910
1234567891011
123456789101112
12345678910111213
1234567891011121314
123456789101112131415
12345678910111213141516
1234567891011121314151617
123456789101112131415161718
12345678910111213141516171819
1234567891011121314151617181920
Answer:
public class Test
{ public static void main (String [] agrs )
{ for (int i =1; i <= 20; i ++)
{ for (int j = 1; j <= i; j++)
System.out.print(j);
System.out.println("");;
}
}
}