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Variables are a place to store values and results. For example, try this:

x = 2
x

What happened? When you typed `x=2`

, MATLAB assigned the value of 2
to the variable `x`

. When you typed `x`

, MATLAB returned the
value of x. Try typing `y`

instead. MATLAB complains
because the variable `y`

has not yet been assigned a value and is
therefore undefined.
It is important (even if you don't understand yet why) *NOT* to read
`x=2`

as ``x equals two.'' *That is not what it means!* To
MATLAB, the statement `x=2`

means ``assign the variable `x`

the
value of 2.'' The `=`

symbol is an *assignment* operator. (The
``equality'' operator is `==`

. Incidentally, this is generally true
for all programming languages, not just MATLAB.)
The `=`

assignment operator works not only for values but also for
expressions. Try,

y = 2+2
z = y*3
a = z+y
b = a+z-y

Make sure you understand why
MATLAB gives the answers it does. Notice that the quantity being assigned
to a variable can even be another variable itself or an expression
including other variables.

**Subsections**

** Next:** 1.4.0.1 Built-in variables
** Up:** 1. Getting started with
** Previous:** 1.3 Matlab as a
** Contents**
Gus Hart
2005-01-28