Programmatically set an Angular control as invalid

To programmatically set an Angular control as invalid, you can use the setErrors() method of the AbstractControl class. This method allows you to set an error object on the control that will indicate that it is invalid.

Here is an example of how you can use setErrors() to set a control as invalid.

In this example, the setControlInvalid() method is used to set the name control as invalid by calling the setErrors() method on it and passing in an error object with the key invalid set to true. This will cause the control to be marked as invalid and will display the appropriate validation message if a validation message is defined for the error key.