Operators

Question 1

What do we need to watch out when using operators?

Answer 1

For usage of = in code

Question 2

Which operators have the highest precedence?

Answer 2

Post-unary operators (expression++, expression–)

Question 3

What comes after post-unary (expression++, expression–) operators in precedence?

Answer 3

Pre-unary operators (++expression, –expression)

Question 4

What is the precedence order of other unary operators (-, !, ~, +, (type)) ?

Answer 4

Other unary operators come after pre-unary operators (++expression, –expression)

Question 5

Where does the cast operator ((Type)reference) fit in the precedence order?

Answer 5

The cast operator has the same precedence as other unary operators (-, !, ~, +, (type))

Question 6

What operators come after unary operators (-, !, ~, +, (type)) in precedence?

Answer 6

Multiplication/division/modulus operators (*, /, %)

Question 7

What is the next level of precedence after multiplication/division/modulus? (*, /, %)

Answer 7

Addition/subtraction operators (+, -)

Question 8

Where do shift operators («,&raquo_space;,&raquo_space;>) fall in the precedence order?

Answer 8

Shift operators («,&raquo_space;,&raquo_space;>) come after addition/subtraction (+, -)

Question 9

What comes after shift operators («,&raquo_space;,&raquo_space;>) in precedence?

Answer 9

Relational operators (<, >, <=, >=, instanceof)

Question 10

What is the precedence of equality operators compared to relational operators? (<, >, <=, >=, instanceof)

Answer 10

Equality operators (==, !=) have lower precedence than relational operators

Question 11

In what order do the bitwise operators come?

Answer 11

After equality operators (==, !=) - Logical AND (&), then Logical XOR (^), then Logical OR (|)

Question 12

Where do conditional AND (&&) and OR (||) fit in the precedence order?

Answer 12

Conditional AND (&&) has higher precedence than conditional OR (||), both come after bitwise operators

Question 13

What is the precedence of the ternary operator?

Answer 13

The ternary operator (?:) comes after conditional OR and before assignment operators

Question 14

Where do assignment operators (=, +=, -=, etc.) fall in the precedence order?

Answer 14

Assignment operators (=, +=, -=, etc.) have one of the lowest precedences

Question 15

What operator has the lowest precedence?

Answer 15

The arrow operator (->) has the lowest precedence

Question 16

What are logical operators?

Answer 16

AND (&), inclusive OR (^) and exclusive OR (|)

Question 17

How does logical AND (&) evaluate?

Answer 17

true if both values are true

Question 18

How does logical inclusive OR (|) evaluate?

Answer 18

false only if both are false

Question 19

How does logical exclusive OR (^) evaluate?

Answer 19

true only if both are different

Question 20

How do we call a part of expression that is not evaluated?

Answer 20

Unperformed side effect

Question 21

What do we need to watch out when using logical operators?

Answer 21

Both values are being evaluated

Question 22

What does unary operator ~ do?

Answer 22

Inverts 0s and 1s in literal

Question 23

How do we calculate result of unary operator ~?

Answer 23

(n * (-1)) - 1

Question 24

Casting with primitives?

Answer 24

Only needed if bigger literal type needs to become smaller literal type

Question 25

What is overflow and underflow?

Answer 25

When casting bigger literal to smaller doesn't fit

Question 26

What do we need to watch out when using instanceOf?

Answer 26

Need to watch if we evaluate instanceOf variable that makes sense (eg. Number cannot be instance of String)

Question 27

null instanceOf Object?

Answer 27

Always false

Question 28

Numeric promotion?

Answer 28

Happens only when statement has numbers, and lower than int are promoted to int, and then calculated

Question 29

null instanceOf null

Answer 29

Exception is thrown

Question 30

lower primitive type + bigger primitive type = ?

Answer 30

bigger primitive type

Question 31

whole number + float = ?

Answer 31

float

Question 32

short + byte = ?

Answer 32

int

Question 33

byte hat = 1; short boots = 2 + hat;

Answer 33

Exception, because of the numeric promotion to int. Need to cast it back to short