# Category: Formula

## FormuIas - Is it possible to call a user-defined function recursively in Power Apps?

Calling a user-defined function recursively is ideal for solving problems that can be broken down into smaller instances of the same problem, and is perfect in scenarios where we need to traverse tree structures. Is it possible to call a user-defined function from Power Apps? Find out in this post!

## Formulas - A beginners guide on how to create and call user-defined functions (UDFs)

If you want to improve your app by defining reusable parameterised functions, this post provides an introductory guide on how to use this new feature.

## Formula - How to add a button that converts degrees Centigrade to Fahrenheit and vice versa

Here's a walkthrough on how we can customise a data entry screen to include a button that carries out unit measurement conversions..

## Formula - How to convert a single delimited string to rows and columns

This post demonstrates a method we can use to convert semi-structured strings to rows and columns.

## Data - How to group data in a gallery and calculate sums

When displaying records in a gallery, it can be very helpful to show the sums of values. This post provides a walk-through on how to carry out this task.

## Formula - How to calculate compound interest

If you need to calculate compound interest from Power Apps, this post describes the formula to carry out this task.

## Utilities - The best way to peform OCR on images of Power Apps Formulas

If you need to convert images of Power App formulas to text, here's a review comparison of some OCR tools that you can use.

## Example - How to use a drop down control to convert currencies

For cases where we want to display values or prices in a different currency, this post describes a simple example of how to use a drop-down box to display the converted value.

## Formula - How to parse JSON in Power Apps- 4 examples

Following the introduction of the ParseJSON function, we can more easily parse JSON for use from within Power Apps. This post highlights the formula to parse 4 typical JSON structures that we may encounter.

## Data - How to get a row by ordinal number

It's now possible to retrieve records from a table, collection, or data source by ordinal number. The function that provides this functionality is called Index, and this post summarises how it works.

## Formula - What to do when the If statement doesn't work?

A question that arises on occasions is - why doesn't my If statement work? This post walks through one of the most common causes and highlights the possible workarounds.

## Formula - Boolean And / Or operators - What is the order of precedence?

When we construct expressions that include the Boolean And and Or operators, which operator takes precedence? Find out in this post.

## Controls - How to set the data source of a Combo Box to a comma separated string

There may be a need to set the data source of a combo box control to a comma-separated list. This post walks through how to carry out this task.

## Numbers - 10 examples of how to round numbers

When we work with numbers with Power Apps, a common requirement is to round numbers. This post summarises the formula to carry out some of the most common rounding requirements, including how to round to multiples, how to round to values such as 0.5, 0.99, 0.45, how to round to odd/even numbers, and how to return the integer portion of a decimal value.

## Formula - Difference between round, square, and curly brackets

For app builders who are relatively new, the syntax for writing formula can be confusing - perticularly with regards to the use of brackets. This post summarises the bracket types that are available in Power Apps.