IsError

How to Use the Power Fx IsErrorĀ  Function in Power Apps

What is the IsError function?

The IsError function is a logical function that returns true if its argument is an error and false otherwise. The function takes a single argument, which can be any expression that returns a value. The IsError function is often used with other Power Fx functions to handle errors and ensure that the app continues to run smoothly.

How to use the IsError function

To use the IsError function in Power Apps, follow these steps:

1. Open the app you want to work on in the Power Apps Studio.

2. Select the control or element where you want to use the IsError function.

3. Click on the formula bar to open the Power Fx editor.

4. Type the IsError function followed by the expression you want to evaluate in parentheses. For example, if you want to check whether a division operation returns an error, you can use the following formula:


5. Press Enter to evaluate the formula. The result will be either true or false, depending on whether the expression returns an error.

6. You can now use the result of the IsError function to take appropriate action. For example, you can display an error message, replace the error value with a default value, or ignore the error and continue with the app's execution.

Examples of using the IsError function

Here are some examples of using the IsError function in Power Apps:

Example 1: Displaying an error message

Suppose you have a form in your app that allows users to enter numbers. You want to ensure that the app does not crash if the user enters a zero as the denominator in a division operation. To achieve this, you can use the IsError function to check whether the denominator is zero and display an error message if it is. Here's how to do it:


This formula checks whether the denominator is zero and displays the error message “Cannot divide by zero” if it is. Otherwise, it returns the result of the division operation.

Example 2: Replacing error values with default values

Suppose you have a gallery in your app that displays a list of products. Some of the products have missing prices, which are represented by blank values. You want to replace these blank values with a default value of 0. To achieve this, you can use the IsError function to check whether the price value is blank and replace it with 0 if it is. Here’s how to do it:


This formula checks whether the price value is blank and replaces it with 0 if it is. Otherwise, it converts the price value to a number using the value function.

The IsError function is a powerful tool for handling errors in Power Apps. It allows you to check whether an expression returns an error and take appropriate action based on the result. By using the IsError function, you can ensure that your app runs smoothly even in the presence of errors. We hope this article has helped you understand how to use the Power Fx IsError function in Power Apps. Happy coding!

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