$3\mathrm{.}1$ Logical variables

While most values in a MATLAB ${?}^{}$ program are numbers, sometimes logical values are useful. A logical value, also known as a Boolean

value, can be only true $($any non$-$zero number, typically $1)$ or false $($printed by MATLAB as a $0).$ In contrast, a numerical value can be any

value, ex: $-1\mathrm{.}8,0,2\mathrm{.}356,27,9009,$ etc. Assigning a logical value to a variable creates a logical variable that can hold only logical values.

Logical variables can be used to test a logical state, namely whether something is either true or false, or to hold the outcome of a logical

or a relational operation, which is discussed elsewhere.

Example $3\mathrm{.}1\mathrm{.}1$: Creating logical variables.

isLarge $=$

logical

$1$

format compact;

isLarge $=$ true

isHeavy $=$

logical

isHeavy $=$ false

num $=9$

whos

$0$

num $=9$

The variables isHeavy and isLarge, assigned logical values true and false, are listed as being of class "logical". Such variables

only occupy one byte each, in contrast to the numerical variable num, which occupies $8$ bytes. The interpreter prints the value true as $1$

and the value false as $0.$