A scripting language for HTML documents - applicable on every possible application. If you need to understand SAP templates or you need to take control over your HTML... SAP uses this language quite a bit themselves and it's a good idea to get your head around the basics of (client-side ) Javascript. Javascript is a scripting language, not to be confused with Java (which is a programming language). Here's a few ideas to what you can accomplish with Javascript:
- Hide/show/position objects such as text blocks or images
- Roll-over effects
- Mouse-click responses
- Open windows (popups) and control them (e.g. Resize, Move, Close)
- Access to the DOM (Document Object Model)
- Calculations
- Access to information such as browser version, etc
And here's the more practical use in "Business Application" terms:
- Make an entry field mandatory
- Perform basic checks such as formatting (e.g. DD/MM/YYYY) and upper limit / lower limit
- Report the errors such as formatting issues, message popups like "Please correct"...
- Hide/show help texts (context sensitive)
- Calculate a total / checksum
- forward the HTML document to another URL
- Ajax access to get additional information onto the page (without having to leave it)