Validating data on inputs with the pattern attribute



September 14, 2020

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Using the 'pattern' attribute to validate inputs

What's up guys? Today we'll check a HTML tip on validating inputs by using the 'pattern' attribute.

The 'pattern' attribute lets us specify a regular expression that must be respected by the input value. So if a user types a value that doesn't fit this regular expression, it won't be submitted. This can be super handy for an initial layer of validation on a form as you'll make the user respect the mandatory types for each input.

<form> <input type="text" placeholder="Has to contain 4 letters and no numbers" pattern="[A-Za-z]{4}" /> <button>Send</button> </form> <form> <input type="password" placeholder="Has to contain 6 characters or more" pattern=".{6,}" /> <button>Send</button> </form> <form> <input type="text" placeholder="Can only contain numbers" pattern="[0-9]+" /> <button>Send</button> </form> <form> <input type="url" placeholder="Must start with https:// or http://" pattern="https?://.+" /> <button>Send</button> </form>

In here we have four examples, each one with a form and an input with different patterns: containing exactly 4 letters and no numbers, containing at least 6 characters, containing only numbers and starting with 'http://' or 'https://'. They are all pretty straightforward so just take a look to check how they are being implemented.

Let me know your thoughts on it! See you guys 😁✌️