Html code for validating forms
This attribute specifies a format (in the form of a Java Script Regular Expression) that the field value is checked against.Regular expressions are a language used for parsing and manipulating text.It is worth noting that relying solely on the browser (client-side) for validation can be dangerous because it can be circumvented by a malicious user or by computer bots.Not all browsers support HTML5, and not all input sent to your script will come from the form.In most cases, however, you should be able to use Google to search for the regular expression you want, or even use a tool to help you.This is a Boolean attribute used to indicate that a given input field’s value is required in order to submit the form.
When it comes to validating form values, it can be done on the client-side (web browser) and on the server-side (using your preferred server-side language).
Let’s see some examples of using regular expressions for validating form field data.
Telephone numbers: As mentioned, the See the Pen Alpha-Numeric Character Validation Example by Site Point (@Site Point) on Code Pen.
Twitter Username This regular expression matches a Twitter username with the leading @ symbol.
For example See the Pen Hex-Color Code Validation Example by Site Point (@Site Point) on Code Pen.
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