5- boolean algebra, boolean and relational operators, branching constructs

Question 1

&&

Answer 1

logical “and”, binary

Question 2

||

Answer 2

logical “or”, binary

Question 3

!

Answer 3

logical “not”, unary

Question 4

==

Answer 4

equal to comparison

Question 5

!=

Answer 5

not equal to comparison

Question 6

> =

Answer 6

greater than or equal to comparison

Question 7

<=

Answer 7

less than or equal to comparison

Question 8

Precedence of operators

Answer 8

()
++ –
unary + -
* / %
+ -
> < >= <= !=
==
&&
|| !
= compound assignment

Question 9

block

Answer 9

a sequence of statements enclosed in curly brackets

Question 10

Variable scope

Answer 10

area in program where a variable can be used

Question 11

Basic id-statement

Answer 11

syntax
if (expression) body
semantics: if the expression is true then execute body
body is either a single statement or a block
example 1:
if (v > 0) v = 0;

example 2:
if (v < 0){
v = -v;
i += 1;
}

Question 12

Programming idiom

Answer 12

a common way of accomplishing a simple task
swapping values of two variables with a third is an idiom

Question 13

If-else statement

Answer 13

syntax
if (expression)
body1
else
body2

semantics
if expression is true then
execute body1 otherwise
execute body2

example
if (v == 0)
cout &laquo_space;“v is 0”;
else
cout &laquo_space;“v is not 0”;

Question 14

Ternary operator

Answer 14

operator accepting three operands

Question 15

Conditional operator

Answer 15

used as an abbreviated form of branching

Question 16

boolean-expression ? true-expression : false-expression

Answer 16

if boolean-expression is true, then the value of whole expression is true-expression, or false-expression otherwise

Question 17

Switch statement

Answer 17

expression of any “countable”
type (int, char)
literal or named constant of
same type as expression

syntax
switch (expression){
case constant:
statements
break;
case constant:
statements
default:
statements
}
semantics
expression is evaluated, execution continues in first matching case
(optional) default matches any expression value
break-statement terminates the switch statement, execution continues with a statement following switch-block
if case does not end with break, execution continues to next case