You need to configure that the mobile app meets the requirements for phone entries. Which expression should you use?

The IsMatch function is used in Power Fx to test whether a text string matches a specified pattern, typically defined by a regular expression. Phone number entries often need to conform to specific formats that can include digits, parentheses, hyphens, and plus signs (e.g., +1 (555) 123-4567). IsMatch is the only function among the options that can validate such complex patterns, making it the correct choice for ensuring phone entries meet formatting requirements.

A. PlainText: This is a function that removes HTML/XML tags from a string. It is used for data sanitization, not for validating the format of an entry.

C. IsType: This function checks if a value is of a specific data type (e.g., Number, Text, Record). It does not validate the format or pattern within a text string.

D. IsNumeric: This function checks if a string contains only numeric characters. It would incorrectly reject valid phone numbers that include non-numeric symbols like (, ), -, or +.

1. Microsoft Learn. (2023). IsMatch, Match, and MatchAll functions in Power Apps.

Section: "IsMatch function"

Content: "The IsMatch function tests whether a text string matches a pattern... Use IsMatch to validate the value of a text-input control before it's saved to a data source." The documentation provides a direct example of using IsMatch with a regular expression to validate a North American phone number format.

2. Microsoft Learn. (2023). Value, IsNumeric, IsBlank, IsEmpty functions in Power Apps.

Section: "IsNumeric function"

Content: "The IsNumeric function tests whether a value is a number... This function can be useful to avoid errors if you want to perform calculations on values that users type in a text-input control." This confirms IsNumeric is for checking if a string can be converted to a number, not for pattern validation of formatted text.

3. Microsoft Learn. (2023). IsType and AsType functions in Power Apps.

Section: "IsType function"

Content: "The IsType function tests whether a value is of a specific type." This clarifies its purpose is type-checking, not format validation.

4. Microsoft Learn. (2023). PlainText function in Power Apps.

Section: "Description"

Content: "The PlainText function removes HTML and XML tags from a string..." This shows its purpose is to strip tags, which is irrelevant to validating a phone number format.