Most modern browsers now support HTML5 Form Validation making it possible to validate form elements without (or before) any Java Script is triggered.The value of a text input box (or a textarea or password input) is available using the syntax that tells you which option has been selected.
I tested your first piece of code on a form and it does not work at all.The problem is that, to have the data submitted in a 'nice' format to the server, the function returns an array containing all the selected checkbox values. In more complicated forms you will want to set conditions on the form that combine multiple elements.Normally you would modify this so that you could submit or not submit the form based on the number of items selected. For example, a text input that only needs to have a value if a checkbox is checked: Using simple logical operators and the functions supplied above you can do all sorts of client-side form validation.It can prevent people from leaving fields blank, from entering too little or too much or from using invalid characters.For an alternative approach to client-side form validation, without Java Script, check out our new article on HTML5 Form Validation which is available now in most modern browsers.To take things a step further you can even explore Ajax Form Validation which lets you supply real-time feedback using server-side scripts triggered by Java Script events.
The team at have made a video based on this article as a part of their Java Script training lessons which you can view below.
This means that if the first Name field is changed and if the value is invalid as per the Angular validation directive e.g. separate error message for maxlength, required, pattern etc.
To implement it, we need to define separate The Mobile numbers can accept only 12 digits (includes country code).
The above shows an error message for the First Name as it must start with a Capital letter.
Validations on email and mobile fields are shown as below: Note that the Submit button will be enabled only when all entries are valid.
Other form values are available using a similar syntax, although this becomes more complicated if you're using SELECT lists, checkboxes or radio buttons (see below for examples). All you need to do is extend the command is encountered, execution of the function is halted.