YES. if it passed js validation that means we have helped the user to enter the right data. We still need server side validations to protect the server/application from malicious users....what if i wanna insert an email into a database, and javascript validation passed and it's a valid email, should i use a further server side validation?...
validation to insert data into DB
Moderators: egami, macek, gesf
Honestly you should use both. Client side validations are there to help a genuine user to enter the right data. Server side validations are mostly there to protect the server from malicious users.