# Documentation

## Create Numeric Arrays

This example shows how to create a numeric variable. In the MATLAB® computing environment, all variables are arrays, and by default, numeric variables are of type `double` (that is, double-precision values). For example, create a scalar value.

`A = 100;`

Because scalar values are single element, 1-by-1 arrays,

`whos A`

returns

```Name Size Bytes Class Attributes A 1x1 8 double ```

To create a matrix (a two-dimensional, rectangular array of numbers), you can use the `[]` operator.

`B = [12, 62, 93, -8, 22; 16, 2, 87, 43, 91; -4, 17, -72, 95, 6]`

When using this operator, separate columns with a comma or space, and separate rows with a semicolon. All rows must have the same number of elements. In this example, `B` is a 3-by-5 matrix (that is, `B` has three rows and five columns).

```B = 12 62 93 -8 22 16 2 87 43 91 -4 17 -72 95 6 ```

A matrix with only one row or column (that is, a 1-by-`n` or `n`-by-1 array) is a vector, such as

`C = [1, 2, 3]`

or

`D = [10; 20; 30]`