Validations Interview Questions on ASP.Net(28)

Validations Interview Questions on ASP.Net(28)

1. Should user input data validation occur server-side or client-side?Why?

A.All user input data validation should occur on the server at a minimum.Additionally, client-side validation can be performed where deemed appropriate and feasable to provide a richer, more responsive experience for the user.

2.How many types of validation controls are provided by ASP.NET ?

A.There are six main types of validation controls.

3.Name two properties common in every validation control?

A.ControlToValidate property and Text property.

4.How do you validate the controls in an ASP .NET page?

A.Using special validation controls that are meant for this. We have Range Validator, Email Validator.

5.Can the validation be done in the server side? Or this can be done only in the Client side?

A.Client side is done by default. Server side validation is also possible. We can switch off the client side and server side can be done.

6.What are the validation controls?

A.A set of server controls included with ASP.NET that test user input in HTML and Web server controls for programmer-defined requirements. Validation controls perform input checking in server code. If the user is working with a browser that supports DHTML, the validation controls can also perform

validation using client script.

7.List the different types of validation controls?

A.There are six types of validation controls.They are:

1.RequiredField Validator

2.Range Validator

3.Compare Validator

4.RegularExpression Validator

5.Custom Validator

6.Validation Summary

8.Define RequiredField Validator?

A.It checks whether the control have any value. It's used when you want the control should

not be empty.

9.Define Range Validator?

A.It checks if the value in validated control is in that specific range. Example TxtCustomerCode should not be more than eight length.

10.Define Compare Validator?

A.It checks that the value in controls should match the value in other control. Example Textbox TxtPie should be equal to 3.14.

11.Define RegularExpression Validator?

A.When we want the control value should match with a specific regular expression.

12.Define Custom Validator?

A.It is used to define UserDefined validation.

13.Define Validation Summary?

A.It displays summary of all current validation errors.

14.How can we force all the validation control to run ?

A.Page.Validate()

15.How can we check if all the validation control are valid and proper ?

A.Using the Page.IsValid() property you can check whether all the validation are done.

16.If client side validation is enabled in your Web page, does that mean server side code is not run?

A.When client side validation is enabled server emit’s JavaScript code for the custom validators. But note that does not mean that server side checks on custom validators do not execute. It does this redundant check two times as some of the validators do not support client side scripting.

17. Which JavaScript file is referenced for validating the validators at the client side ?

A.WebUIValidation.js javascript file installed at “aspnet_client” root IIS directory is used to validate the validation controls at the client side.

18. How to disable client side script in validators?

A.Set EnableClientScript to false.

19.How can I show the entire validation error message in a message box on the client side?

A.In validation summary set “ShowMessageBox” to true.

20.How can you display all validation messages in one control?

A.The ValidationSummary control displays all validation messages in one control.

21.Can you set which type of comparison you want to perform by the CompareValidator control?

A.Yes, by setting the Operator property of the CompareValidator control.

22.Where should the data validations be performed-at the client side or at the server side and why?

A.Data validations should be done primarily at the client side and the server-side validation should be avoided because it makes server task overloaded. If the client-side validation is not available, you can use server-side validation. When a user sends a request to the server, the validation controls are invoked to check the user input one by one.

23.What is the function of the CustomValidator control?

A.It provides the customize validation code to perform both client-side and server-side validation.

24.Which data type does the RangeValidator control support?

A.The data types supported by the RangeValidator control are Integer, Double, String, Currency, and Date.

25. How can you check if all the validation controls on a Web page are valid and proper?

A.You can determine that all the validation controls on a Web page are properly working by writing code in the source file of the Web page using a scripting language, such as VBScript or JavaScript. To do this task, you have to loop across validators collection of pages and check the IsValid property of each validation control on the Web page to check whether or not the validation test is successful.

26.Which control will you use to ensure that the values in two different controls match?

A.You should use the CompareValidator control to ensure that the values in two different controls match.

27. How do you prevent a validation control from validating data at the client end?

A.You can prohibit a validation control to validate data at the client side by setting the EnableClientScript property to False.

28.Can we validate a DropDownList by RequiredFieldValidator?

A.Yes, we can validate a DropDownList by RequiredFieldValidator. To perform this validation, we have to set the InitialValue property of RequiredFieldValidator control.