Following are 3 types of client-side validation:
1. Field cannot be empty. There must be any value.
2. Format must be valid. Like: age is numeric.
3. Values must be with in valid range. Like: age should not be negative and
month should be between 1 to 12.
Client-side validation refers to the validation of user input within the user’s browser before the data is submitted to the server. It helps improve user experience by providing immediate feedback to users without requiring a round trip to the server. There are several types of client-side validation techniques commonly used in web development:
- Data Type Validation: Ensuring that the data entered matches the expected data type, such as numbers, dates, or email addresses.
- Required Field Validation: Checking if mandatory fields in a form are filled out before submission.
- Length Validation: Verifying that the length of input falls within acceptable limits, such as minimum and maximum characters for a password.
- Pattern Matching Validation: Validating input against a specific pattern, like a regular expression. For example, validating a phone number in a specific format.
- Range Validation: Checking if the entered value falls within a certain range, such as a minimum and maximum value for age or price.
- Comparison Validation: Comparing values in different fields, for instance, ensuring that the “confirm password” field matches the original password field.
- Custom Validation: Implementing custom validation logic tailored to specific application requirements.
When asked in an interview, it’s good to elaborate on each type of validation and provide examples or scenarios where each might be applied. Additionally, mentioning the importance of server-side validation alongside client-side validation for security and robustness would demonstrate a deeper understanding of the topic.