Programming and Graphics

3.3 Control structures 53

3.3 Controlstructures

Control structures are blocks of statements that implement short algorithms
and make logical decisions based on available options. An algorithm is a set of
instructions that achieves a goal through sequential or repetitive steps.

C++ employs control structures with single or multiple statements. The
former are simply stated, while the latter are enclosed by curly bracket delim-
iters,{}.

• if statement:

Theifstatement implements conditional execution of one command or

a block of commands.

For example, we may write

if(a==10)

b=10;

or

if(a==10)

{

b=10;

}

If more than one statements is involved, the use of curly brackets is manda-

tory:

if(a!=10)

{

b=a+3;

c=20;

}

We highly recommend using the curly brackets even in the case of one

statement.

• if/else structure:

Theif/elsestructure implements conditional execution based on two

options.

For example, we may write:

if(a!=10)

{