5 .java script events
- 1. JavaScript - Events Prof. Neeraj Bhargava Kapil Chauhan Department of Computer Science School of Engineering & Systems Sciences MDS University, Ajmer
- 2. What is an Event ? JavaScript's interaction with HTML is handled through events that occur when the user or the browser manipulates a page. When the page loads, it is called an event. When the user clicks a button, that click too is an event. Other examples include events like pressing any key, closing a window, resizing a window, etc.
- 3. Cont.. Developers can use these events to execute JavaScript coded responses, which cause buttons to close windows, messages to be displayed to users, data to be validated, and virtually any other type of response imaginable. Events are a part of the Document Object Model (DOM) and every HTML element contains a set of events which can trigger JavaScript Code.
- 4. onclick Event Type This is the most frequently used event type which occurs when a user clicks the left button of his mouse. You can put your validation, warning etc., against this event type. <html> <head> <script type = "text/javascript"> <!-- function sayHello() { alert("Hello World") } //--> </script> </head> <body> <p>Click the following button and see result</p> <form> <input type = "button" onclick = "sayHello()" value = "Say Hello" /> </form> </body> </html>
- 5. onsubmit Event Type onsubmit is an event that occurs when you try to submit a form. You can put your form validation against this event type.
- 6. onmouseover and onmouseout <html> <head> <script type = "text/javascript"> <!-- function over() { document.write ("Mouse Over"); } function out() { document.write ("Mouse Out"); } //--> </script> </head> <body> <p>Bring your mouse inside the division to see the result:</p> <div onmouseover = "over()" onmouseout = "out()"> <h2> This is inside the division </h2> </div> </body> </html>
- 7. Onchange input event <html> <head> <script> function myFunction() { var x = document.getElementById("fname"); x.value = x.value.toUpperCase(); } </script> </head> <body> Enter your name: <input type="text" id="fname" onchange="myFunction()"> <p>When you leave the input field, a function is triggered which transforms the input text to upper case.</p> </body> </html>
- 8. Assignment Explain javascript event with suitable example.