## Explanation

In this example, the goal is to join two one-dimensional ranges together horizontally. This can be done with the CHOOSE function and array constant.

### The CHOOSE function

The CHOOSE function is used to select arbitrary values by numeric position. CHOOSE is a flexible function and accepts a list of text values, numbers, cell references, in any combination. For example, if we have the colors "red", "blue", and "green", we can use CHOOSE like this:

```
=CHOOSE(1,"red", "blue", "green") // returns "red"
=CHOOSE(2,"red", "blue", "green") // returns "blue"
=CHOOSE(3,"red", "blue", "green") // returns "green"
```

If we give CHOOSE an array constant like {1,2}, CHOOSE will return the first and second values in an array at the same time:

```
=CHOOSE({1,2}},"red", "blue", "green") // returns {"red","blue"}
```

The result is an array that contains two values and, in the dynamic array version of Excel, these values spill onto the worksheet into the range G5:H16.

### Applications

Traditionally, the use of CHOOSE function to combine ranges is used up in tricky array formulas. The formulas below are good examples:

In these formulas, the CHOOSE function is used to create a *new* table (in memory) that can be used by the VLOOKUP function to workaround a difficult problem.

*Note: the forthcoming HSTACK function will make this use of CHOOSE unnecessary.*