How To Use FIRSTN,LASTN And INDEX Formula In Canvas Apps (Power Fx)

Introduction

In this article, we are going to see about what PowerApps Formula reference and how it is useful to develop Power Platform Applications.

PowerApps is a service-oriented application used for developing custom apps for your organization.

Easily develop mobile and web apps for any business need—even if you have no technical or development experience—with Power Apps. 

PowerApps helps us create simple apps quickly. Through PowerApps templates, we can customize our applications. With PowerApps, we can connect to our company data coming from

  • Oracle
  • SAP
  • Salesforce
  • Office365
  • Azure
  • Excel/CSV Files

It simplifies the development cycle of the business apps and equips the business users and developers to build custom native, mobile, and web applications.

Launch Canvas App

The steps are given below to create a Power App based on On-Premises data.

  • Login to Office 365 SharePoint site and click the list, where you want to add PowerApps.
  • Click PowerApps link in the list ribbon given below.
  • Enter the PowerApps name and it will redirect to the PowerApps Studio.

Click blank App.

Power Fx

  1. Microsoft Power Fx is the new name for the formula language for canvas app
  2. Power Fx is expressed in human-friendly text.
  3.  It's a low-code language that makers can work with directly in an Excel-like formula bar or Visual Studio Code text window.

In this article, we are going to test below PowerFx formulas with real-time example.

  • FirstN
  • LastN
  • Index

Here, I have created a Table with sample collection on APP start of the PowerApps Application.

Create a simple Collection to Load the values into Table for our testing

Add Data Table to display the Collection to view

FirstN

The FirstN function returns the first set of records of a table; the second argument specifies the number of records to return.

FirstN(colDemoFormula)

OutPut

FirstN(colDemoFormula,2)

This will return the first two records from the table.

Output

LastN

The LastN function returns the first set of records of a table; the second argument specifies the number of records to return.

Syntax

LastN(colDemoFormula)

Output

Output 2

LastN(colDemoFormula,2)

Index

The Index function returns a record of a table based on its ordered position in the table

Index(colDemoFormula,2)

Output

Output 2

Index Formula you can extract Price Column separately,

Index(colDemoFormula,2).Car &"-"&Index(colDemoFormula,2).Price

  1. How To Use Formulas And Functions In PowerApps(Power Fx)
  2. How To Use AddColumns, RenameColumns, DropColumns, ShowColumns Formula In Canvas APPs(Power Fx)?

Conclusion

PowerFx is a language, and anybody can learn with basic logical thinking ideas on the programming side. PowerApps gives you the ability to connect with all kinds of data, which is not only available with your Tenant but connected to it via the Data Management Gateways.

PowerApps is truly the future of building custom forms and then making them available on mobile devices for your organization.

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