The image is from the painter John Atkinson Grimshaw and is called Shipping on the Clyde. year 1881 Oil on cardboard. 30.5 x 51 cm

This will be a brief post about data validation.

If you wanna know more about XSS check THIS

If you wanna know more about HTML injection chech THIS

check THIS LINK to know more about why this works and THIS LINK for a semi related info

And thats it, a basic implementation to validate user input. You can continue modiying this code, but if you have to validate a lot of data, I recommend using known and tested libaries such as Validate.js or Validator.js

Thanks for reading!