Sun. Aug 14th, 2022

# MATLAB – Basic Syntax

MATLAB environment behaves like a super-complex calculator. You can enter commands at the >> command prompt.

MATLAB is an interpreted environment. In other words, you give a command and MATLAB executes it right away.

## Hands on Practice

Type a valid expression, for example, Live Demo

`5 + 5`

And press ENTER

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```ans = 10
```

Let us take up few more examples − Live Demo

`3 ^ 2	       % 3 raised to the power of 2`

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```ans = 9
```

Another example, Live Demo

```sin(pi /2)	  % sine of angle 90o
```

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```ans = 1
```

Another example, Live Demo

`7/0		      % Divide by zero`

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```ans = Inf
warning: division by zero
```

Another example, Live Demo

`732 * 20.3	`

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```ans =  1.4860e+04
```

MATLAB provides some special expressions for some mathematical symbols, like pi for π, Inf for ∞, i (and j) for √-1 etc. Nan stands for ‘not a number’.

## Use of Semicolon (;) in MATLAB

Semicolon (;) indicates end of statement. However, if you want to suppress and hide the MATLAB output for an expression, add a semicolon after the expression.

For example, Live Demo

```x = 3;
y = x + 5```

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

```y =  8
```

The percent symbol (%) is used for indicating a comment line. For example,

`x = 9	     % assign the value 9 to x`

You can also write a block of comments using the block comment operators % { and % }.

## Commonly used Operators and Special Characters

MATLAB supports the following commonly used operators and special characters −

OperatorPurpose
Minus; subtraction operator.
*Scalar and matrix multiplication operator.
.*Array multiplication operator.
^Scalar and matrix exponentiation operator.
.^Array exponentiation operator.
\Left-division operator.
/Right-division operator.
.\Array left-division operator.
./Array right-division operator.
:Colon; generates regularly spaced elements and represents an entire row or column.
( )Parentheses; encloses function arguments and array indices; overrides precedence.
[ ]Brackets; enclosures array elements.
.Decimal point.
Ellipsis; line-continuation operator
,Comma; separates statements and elements in a row
;Semicolon; separates columns and suppresses display.
%Percent sign; designates a comment and specifies formatting.
_Quote sign and transpose operator.
._Nonconjugated transpose operator.
=Assignment operator.

## Special Variables and Constants

MATLAB supports the following special variables and constants −

NameMeaning
epsAccuracy of floating-point precision.
i,jThe imaginary unit √-1.
InfInfinity.
NaNUndefined numerical result (not a number).
piThe number π

## Naming Variables

Variable names consist of a letter followed by any number of letters, digits or underscore.

MATLAB is case-sensitive.

Variable names can be of any length, however, MATLAB uses only first N characters, where N is given by the function namelengthmax.

The save command is used for saving all the variables in the workspace, as a file with .mat extension, in the current directory.

For example,

```save myfile
```

```load myfile