| JavaScript is a versatile programming language … if you know it, you can learn others |
| Without JavaScript, HTML is quite limited | |||
| Only static page-layouts are possible | |||
| JS allows | |||
| Adaptivity … the page can be customized to the browser, site, user, etc. | |||
| Interactivity … users can give information and a response can be displayed: Memory Bank | |||
| Applications … tasks unrelated to documents can be created | |||
| Animations | |||
| Notice the standard HTML process | |||
| HTML is parsed -- read & “decoded” | |||
| During parse JavaScript runs … allowing it to generate HTML, e.g. document.write() | |||
| Browser generates the page from HTML | |||
| After page generated, all is quiet until an event happens, caused by user or timer | |||
| Event handlers handle the events, and then all is quiet again | |||
| Analyze the process for Purple Con | |||
| HTML is parsed | |||
| JavaScript runs … | |||
| HTML generated | |||
| Browser makes page | |||
| All is quiet except for | |||
| events from user | |||
| Event handlers handle | |||
| events, quiet returns | |||
| Analyze the process for an animation | |||
| HTML is parsed | |||
| JavaScript runs … | |||
| HTML generated | |||
| Browser makes page | |||
| All is quiet except for | |||
| events from timer | |||
| Event handlers handle | |||
| events, quiet returns | |||
| JS is a “modern” programming language like C, C++, Java, etc. | |||
| Expect to find numbers, strings, Booleans, | |||
| Variables (of same form) must be declared | |||
| There are if-statements & else-statements | |||
| There is a for-statement | |||
| for (j=0; j<5; j++){ | |||
| <statement list> | |||
| } | |||
| Can you create an animation? | |
| Can you take in data and compute answers? | |
| Got questions? |
| Consider ... | |
| Bubbles ... | |
| JavaScript can build Web pages, process forms and animate … it’s a whole lot more interesting than HTML! |