W1: Expressions

Question 1

How does evaluating expressions work?

Answer 1

The ALU (Arithmetic-logic-unit) evaluates the instructions on integer values
The FPA evaluates the instructions on floating-point values.

Question 2

What expressions can the ALU process on integer types?

Answer 2

Arithmetic
Relational
Logical

Question 3

Arithmetic expressions consist of:

Answer 3

Integral operands for processing by the ALU

Floating point operands for processing by the FPA

Question 4

What are the binary operations on integral (int and char) operands?

Answer 4

operand + operand
operand -  operand
operand * operand
operand / operand
operand % operand - remainder of the division of left by right (division produces a whole number)

Question 5

What are the unary operations on integral operands?

Answer 5

+ evaluates to the operand

- changes the sign of the operand

Question 6

What are the binary operations on floating-point operands?

Answer 6

operand + operand
operand - operand
operand * operand
operand / operand

Question 7

What are the unary operations for floating-point operands?

Answer 7

+ operand evaluates to the operand

- operand changes the sign of the operand

Question 8

What are relational expressions?

Answer 8

C language supports 6 relational operations. A relational operation evaluates a condition. It compared two values and produces ‘1’ if the condition is true and ‘0’ if the value is false. The value is a type of int.

Question 9

What are the 6 relational operations?

Answer 9

operand == operand: equal in value
operand > operand: left is greater than right
operand >= operand: left is greater than or equal to right
operand < operand: left is less than the right
operand <= operand: left is less than or equal to right
operand != operand: left is not equal to the right

Question 10

What values represent true and false in C language?

Answer 10

0 for false

Any other value for true

Question 11

Logical expressions take one of these forms:

Answer 11

operand && operand: both operands are true
operand || operand: one of the operands is true
operand ! operand: the operand is not true

Question 12

What is deMorgan’s law?

Answer 12

A handy rule for converting conditions in logical expressions

“The opposite of a compound condition is the compound condition with all sub-conditions reversed, all &&s changed to ||s and vice versa”

Question 13

What is a shorthand assignment?

Answer 13

Shorthand operators that combine an arithmetic expression with an assignment expression. The arithmetic expression is stored in the left operand.

Question 14

What are the 5 binary shorthand assignment operators for integral operands?

Answer 14

Operand (operators) Operand
I += 4, i = i - 4 : add 4 to I and assign to I
I -= 4, I = I - 4: subtract 4 from I and assign to I
*=
/=
%=

Question 15

What are the 4 unary operands for shorthand assignments?

Answer 15

++I : increment I by 1
I++
–i: decrement I by 1
I–

Question 16

What are the binary shorthand assignment operators for floating-point operands?

Answer 16

*=
/=

Question 17

Unary operands for shorthand assignment operators for floating-point operands

Answer 17

++x increment by x
X++
–x decrement by x
X–

Question 18

What is casting?

Answer 18

The conversion from one type to another. To convert, make the operand with the target type enclosed within parentheses ( )
Ex. (float) operand

Question 19

The C language uses the following ranking:

Answer 19

Long double (higher)
Double
Float
Long long
Long
Int
Short
Char (lower)