MATLAB Data Types

MATLAB exposes numeric, character array, and string data types.

Numeric

All numeric variables are arrays. Colloquially, an array with a single element is called a scalar.

By default, all numeric values are stored as double-precision floating point. Other storage sizes are available however.

x = 3;
y = [3 5];

A shorthand for an array of sequential numbers (with an optional step parameter) is:

a = 5:8;
b = 20:2:24;

Storage Size

To declare a numeric array with a specific storage size, try:

y = uint64(10);

These declaration functions include:

• double()

• single()

• int8()

• int16()

• int32()

• int64()

• uint8()

• uint16()

• uint32()

• uint64()

Type Casting

The cast function is used to change the storage size of a numeric array. Try:

b = cast(a,"uint8");

The second argument must be one of:

• "single"

• "double"

• "int8"

• "int16"

• "int32"

• "int64"

• "uint8"

• "uint16"

• "uint32"

• "uint64"

• "logical"

• "char"

Character Array

Character arrays store a sequence of characters. They are declared like:

c = 'Hello World';

String

All string variables are arrays. Colloquially, a string array with a single element is called a string scalar.

str = "Greetings friend"
str = ["Greetings friend" "Hello, world"]

To convert a numeric array into a string array, try:

>> str = string([1 24 356]);

str = 1x3 string

   "1"          "24"          "356"

Symbolic Variable

Symbolic variables are created like:

% Declaring symbolic variables.
syms x y;

% Defining symbolic expressions.
f = (x^2 + y^2);

% Defining symbolic functions.
f(x,y) = (x^2 + y^2);

Symbolic functions can then be evaluated for input values.

Symbolic expressions are very similar, but can be used to define a surface to plot or to solve a system.

% Define a quadratic equation.
f = a*x^2 + b*x + c

% Solve for roots of a quadratic equation.
x_0 = solve(f == 0, x);

Function Handle

Function handles are created like:

% Declaring symbolic variables needed by the function handle.
syms x y z;

f = @(x,y,z) (x.^2 + y.^2 + z.^2);

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