only allow numbers kotlin

To only allow numbers in Kotlin, you can use regular expressions to validate user input. Here are the steps to achieve this:

1. Create a regular expression pattern: In Kotlin, you can use the Regex class to define a pattern that matches numbers. For example, you can use the pattern \d+ to match one or more digits.

2. Validate user input: To ensure that the input only contains numbers, you can use the matches function of the Regex class. This function returns true if the input matches the specified pattern, and false otherwise. You can apply this function to the user input to validate it.

3. Handle validation result: Depending on the validation result, you can perform different actions. If the input matches the pattern, you can proceed with further processing. Otherwise, you can display an error message or prompt the user to enter a valid number.

By following these steps, you can ensure that only numbers are allowed in Kotlin. Remember to handle any potential exceptions or edge cases that may arise during the validation process.