# cat

Concatenate arrays along specified dimension

## Syntax

`C = cat(dim, A, B)C = cat(dim, A1, A2, A3, A4, ...)`

## Description

`C = cat(dim, A, B)`concatenates the arrays `A` and `B` along array the dimension specified by `dim`. The `dim` argument must be a real, positive, integer value.

`C = cat(dim, A1, A2, A3, A4, ...)` concatenates all the input arrays (`A1`, `A2`, `A3`, `A4`, and so on) along array dimension `dim`.

For nonempty arrays, `cat(2, A, B)` is the same as `[A, B]`, and `cat(1, A, B)` is the same as `[A; B]`.

If your input arrays are tables, `dim` must be either 1 or 2. `cat` then concatenates by calling `horzcat` or `vertcat` respectively.

## Examples

Given

```A = B = 1 2 5 6 3 4 7 8 ```

concatenating along different dimensions produces

The commands

```A = magic(3); B = pascal(3); C = cat(4, A, B);```

produce a 3-by-3-by-1-by-2 array.

expand all

### Tips

When used with comma-separated list syntax, ```cat(dim, C{:})``` or `cat(dim, C.field)` is a convenient way to concatenate a cell or structure array containing numeric matrices into a single matrix.

You can concatenate categorical arrays with cell arrays of strings. For more information, see Combine Categorical Arrays.

If all the input arrays are ordinal categorical arrays, they must have the same sets of categories including their order. For more information, see Ordinal Categorical Arrays.

You can concatenate datetime arrays with cell arrays of strings.

You can concatenate duration arrays and calendar duration arrays. The result is a calendar duration array.

You can concatenate duration or calendar duration arrays with numeric arrays. Prior to concatenation, MATLAB® converts the numeric array to an array of equivalent days using the `days` function.

For information on combining unlike integer types, integers with nonintegers, cell arrays with non-cell arrays, or empty matrices with other elements, see Valid Combinations of Unlike Classes