Servis-Rhino 4211B Betriebsanweisung PDF herunterladen (Seite 133)

• setInterval(function, interval) - Calls a function repeatedly every timer

period

• setTimeout(function, interval) - Calls a function once after a time period

The time periods are expressed in milliseconds.

Both these functions return a handle which can be used to cancel or stop the firing of events.

passing the handle into the function "clearTimeout(handle)" will cancel the previous timer.

JSON Data representation

In JavaScript source code, JavaScript objects can be declared using the language syntax. This

syntax is surprisingly flexible. When one wants to pass data from one application to another, an

encoding has been defined called "JSON" which is essentially encoding a tree of data into a single

string which looks like the definition of a JavaScript object in source.

JSON within JavaScript

JSON within Java

See also:

• Wikipedia – ISO 8601

• Dojo Dates and Times

Debugging in the browser

Since the majority of web execution occurs within the browser itself, we need good tools and

techniques for debugging our code within that environment. Fortunately, all the modern browsers

come supplied with development tools that assist with debugging.

Of the features that are available, some are more important than others. The first I wish to discuss

is the console log. Although this can be used to log your own diagnostics statements, it is also

where the browser itself logs information. If a JavaScript error is encountered during evaluation, it

is within the console log that we will learn this.

The second area that is of importance is are the JavaScript debuggers. We can set breakpoints

within our JavaScript code such that when these breakpoints are encountered during execution, the

debugger will kick in and show us that we have reached the breakpoint. In addition, we can

Page 133

1 2 ... 128 129 130 131 132 133 134 135 136 137 138 ... 297 298

Keine Kommentare

Servis-Rhino 4211B Betriebsanweisung Seite 133