Lec 3: Numbers and Math

Question 1

What is a literal

Answer 1

A constant value that appears directly in a program

Question 2

What is the storage size of a byte?

Answer 2

8 bit signed

Question 3

What is the storage size of a short?

Answer 3

16 bit signed

Question 4

What is the storage size of an int?

Answer 4

32 bit signed

Question 5

What is the storage size of a long

Answer 5

64 bit signed

Question 6

What is the storage size of a float

Answer 6

32 bit IEEE 754

Question 7

What is the storage size of a double

Answer 7

64 bit IEEE 754

Question 8

True or false: Int variables store numbers accurately?

Answer 8

True

Question 9

True or false: float numbers store numbers accurately?

Answer 9

False

System.out.println(1.0-0.9); gives 0.09999999998 and not 0.1

Question 10

What data type is truncated when divided with itself?

Answer 10

Int

5/2 yields 2

Question 11

What is truncated

Answer 11

not to be mistaken with rounding
returns the int down

5/2 yields 2

Question 12

math operative conversion rules

Answer 12

If one operand is double, the other is converted to double
otherwise if one is float, the other is converted into float
otherwise if one is long, the other is converted to long

Question 13

True or False: When casting a double to int, it truncates

Answer 13

True

Question 14

Operator precedence

Answer 14

• (), var++, var–
• ++var, –var, +, - (unary plus and minus), ! (not)
• (type) casting
• *, /, % (multiplication, division, and remainder)
• +, - (binary addition and subtraction)
• <, <=, >, >= (relational operators)
• ==, != (equality)
• ^ (exclusive or)
• && (and)
• || (or)
• =, +=, -=,*=, /=, %= (assignment operators)

Question 15

how to import java scanner to listen to input

Answer 15

import java.util.Scanner

Question 16

What does Math.ceil(3.5) return?

Answer 16

4.0

Question 17

What does Math.floor(3.5) return?

Answer 17

3.0

Question 18

Does Math.sin() take in degrees or radians?

Answer 18

radians

Question 19

Does Math.round(3.6) return a double?

Answer 19

No, it returns an int

Question 20

Does Math.rint(3.6) return a double?

Answer 20

Yes, it returns 4.0

Question 21

What does Math.ceil(3.6) return?

Answer 21

4.0