17 - Expressions

Question 1

refers to the means of specifying computations in a program

Answer 1

expressions

Question 2

operators can be (3)

Answer 2

1. unary (single operand)
2. binary (two operands)
3. ternary (three operands)

Question 3

types of expressions (3)

Answer 3

1. arithmetic
2. relational
3. boolean

Question 4

on types of expressions:

used to specify mathematical computations

Answer 4

arithmetic expressions

Question 5

on types of expressions:

used to compare two values

Answer 5

relational expressions

Question 6

on types of expressions:

used for boolean operations and may sometimes require operands to be of boolean type

Answer 6

boolean expressions

Question 7

design issues of expressions (4)

Answer 7

1. operator evaluation order
2. operand evaluation order
3. operator overloading
4. type conversions

Question 8

on design issues of expressions:

partially define what order the operators would be executed

Answer 8

operator evaluation order

Question 9

on design issues of expressions:

defines which use of variables in the expression create a side-effect

Answer 9

operand evaluation order

Question 10

occurs when a subprogram changes the value of an operand that will be used later in the expression

Answer 10

side-effect

Question 11

solutions to side-effect (2)

Answer 11

1. disallow functions to have expressions that might cause side-effects
2. have an order when expressions are to be evaluated

Question 12

on design issues of expressions:

operators having multiple uses

Answer 12

operator overloading

Question 13

on design issues of expressions:

whether we should allow a programmer to define a different operation for an operator

Answer 13

operator overloading

Question 14

on design issues of expressions:

are values allowed to be converted

Answer 14

type conversions

Question 15

conversion to a type that can store all approximations of the original type

Answer 15

widening conversion

Question 16

conversion to a type that cannot even store approximations of the original type

Answer 16

narrowing conversion

Question 17

type of conversion that is done by the compiler based on the operand types

Answer 17

implicit type conversion (coercion)

Question 18

type of conversion that is requested by the programmer

Answer 18

explicit type conversion (typecast)

Question 19

types of conversion (4)

Answer 19

1. widening conversion
2. narrowing conversion
3. implicit type conversion (coercion)
4. explicit type conversion (typecast)

Question 20

happens when the result is determined without completely evaluating the expression

Answer 20

short-circuit evaluation

Question 21

allows the programmer to dynamically change the binding of values to variables

Answer 21

assignment statements

Question 22

types of assignment statements (5)

Answer 22

1. simple assignment
2. conditional targets
3. compound assignment
4. unary assignment
5. multiple assignments

Question 23

what type of assignment statement is shown below?

number = 124

Answer 23

simple assignment

Question 24

what type of assignment statement is shown below?

if flag:
    a = 0
else:
    b = 0

Answer 24

conditional targets

Question 25

what type of assignment statement is shown below? count += 1

Answer 25

compound assignments

Question 26

what type of assignment statement is shown below? count++;

Answer 26

unary assignments

Question 27

what type of assignment statement is shown below? a, b = "Hello", 124

Answer 27

multiple assignments

Question 28

in some languages, assignment statements return the __ assigned to the variable

Answer 28

value