List all correct answers where applicable. 1. Analyze the following code: boolean even = false; if (even = true) { System.out.println("It is even"); } a. The program has a compile error. b. The program has a runtime error. c. The program runs fine but displays nothing. d. The program runs fine and displays It is even. 2. Suppose x = 1, y = -1, and z = 1. What is the output of the following statement? if (x > 0) if (y > 0) System.out.println("x > 0 and y > 0"); else if (z > 0) System.out.println("x < 0 and z > 0"); a. x > 0 and y > 0; b. x < 0 and z > 0; c. x < 0 and z < 0; d. no output. 3. Suppose isPrime is a boolean variable, which of the following are correct for testing if isPrime is true. a. if (isPrime = true) b. if (isPrime == true) c. if (isPrime) d. if (!isPrime = false) e. if (!isPrime == false)
Operations
In mathematics and computer science, an operation is an event that is carried out to satisfy a given task. Basic operations of a computer system are input, processing, output, storage, and control.
Basic Operators
An operator is a symbol that indicates an operation to be performed. We are familiar with operators in mathematics; operators used in computer programming are—in many ways—similar to mathematical operators.
Division Operator
We all learnt about division—and the division operator—in school. You probably know of both these symbols as representing division:
Modulus Operator
Modulus can be represented either as (mod or modulo) in computing operation. Modulus comes under arithmetic operations. Any number or variable which produces absolute value is modulus functionality. Magnitude of any function is totally changed by modulo operator as it changes even negative value to positive.
Operators
In the realm of programming, operators refer to the symbols that perform some function. They are tasked with instructing the compiler on the type of action that needs to be performed on the values passed as operands. Operators can be used in mathematical formulas and equations. In programming languages like Python, C, and Java, a variety of operators are defined.
List all correct answers where applicable.
1. Analyze the following code:
boolean even = false;
if (even = true) {
System.out.println("It is even");
}
a. The
b. The program has a runtime error.
c. The program runs fine but displays nothing.
d. The program runs fine and displays It is even.
2. Suppose x = 1, y = -1, and z = 1. What is the output of the following statement?
if (x > 0)
if (y > 0)
System.out.println("x > 0 and y > 0");
else if (z > 0)
System.out.println("x < 0 and z > 0");
a. x > 0 and y > 0;
b. x < 0 and z > 0;
c. x < 0 and z < 0;
d. no output.
3. Suppose isPrime is a boolean variable, which of the following are correct for testing if isPrime is true.
a. if (isPrime = true)
b. if (isPrime == true)
c. if (isPrime)
d. if (!isPrime = false)
e. if (!isPrime == false)
4. Which of the following are possible output from invoking Math.random()?
a. 3.43
b. 0.5
c. 0.0
d. 1.0
5. Suppose you write the code to display "Cannot get a driver's license" if age is less than 16 and "Can get a driver's license" if age is greater than or equal to 16. Which of the following code are correct?
I:
if (age < 16)
System.out.println("Cannot get a driver's license");
if (age >= 16)
System.out.println("Can get a driver's license");
II:
if (age < 16)
System.out.println("Cannot get a driver's license");
else
System.out.println("Can get a driver's license");
III:
if (age < 16)
System.out.println("Cannot get a driver's license");
else if (age >= 16)
System.out.println("Can get a driver's license");
IV:
if (age < 16)
System.out.println("Cannot get a driver's license");
else if (age > 16)
System.out.println("Can get a driver's license");
else if (age == 16)
System.out.println("Can get a driver's license");
a. I
b. II
c. III
d. IV
6. Assume x = -4, which of the following is true?
a. !(x == 4)
b. x != 4
c. x == 5
d. x != 5
7. To obtain the arc sine of 0.5 degree, use _______.
a. Math.asin(0.5)
b. Math.asin(Math.toDegrees(0.5))
c. Math.asin(Math.toRadians(0.5))
d. Math.sin(0.5)
8. What is the value of the following expression?
true || true && false
a. true
b. false
9. What is y displayed in the following code?
public class Test1 {
public static void main(String[] args) {
int x = 1;
int y = x = x + 1;
System.out.println("y is " + y);
}
}
a. y is 0.
b. y is 1 because x is assigned to y first.
c. y is 2 because x + 1 is assigned to x and then x is assigned to y.
d. The program has a compile error since x is redeclared in the statement int y = x = x + 1
10. Analyze the following program fragment:
int x;
double d = 1.5;
switch (d) {
case 1.0: x = 1;
case 1.5: x = 2;
case 2.0: x = 3;
}
Which of these is correct about the above code?
a. The program has a compile error because the required break statement is missing in the switch statement.
b. The program has a compile error because the required default case is missing in the switch statement.
c. The switch control variable cannot be double.
d. No errors.
11. What is y after the following statement is executed?
x = -1;
y = (x < 0) ? -2 : 3;
a. -3
b. -2
c. 3
d. 0
e. Illegal expression
12. What is the output of the following code?
boolean even = false;
System.out.println((even ? "true" : "false"));
a. true
b. false
c. nothing
d. true false
13. What is Math.floor(3.6)?
a. 3.0
b. 3
c. 4
d. 5.0
14. Which of the following assignment statements is correct?
a. char c = 'dn';
b. char c = 100;
c. char c = ‘m’;
d. char c = "100";
15. Which of the following are valid identifiers?
a. $failure
b. public
c. 988ht
d. 8=9
e. radius
16. The expression "CS " + 1 + 0 + 3 evaluates to ________.
a. CS103
b. CS4
c. CS 103
d. cs 123
e. Illegal expression.
17. Suppose s6 and s5 are two strings. What is the result of the following code?
s6.equals(s5) == s5.equals(s6)
a. true
b. false
18. What is the return value of "PROGRAM".substring(0, 6)?
a. "PROGRAM"
b. "PROGRA"
c. "PROG"
d. "ROGRAM"
19. Given that A is 0011 0101, What is the decimal (not binary) value of B and C?
B = A<<2
C = A>>3
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