There is one more thing to discuss before we explore bigger and better
things beyond “Hello World!” In this book, we have implemented a very
simple debugging methodology using the console.log
functionality of modern web
browsers. This function lets you log text messages to the JavaScript
console to help find problems (or opportunities!) with your code. Any
browser that has a JavaScript console (Chrome, Opera, Safari, Firefox with
Firebug installed) can make use of console.log
. However, browsers without console.log
support throw a nasty error.
To handle this error, we use a wrapper around console.log
that makes the call only if the
function is supported. The wrapper creates a class named Debugger
and then creates a static function
named Debugger.log
that can be called
from anywhere in your code, like this:
Debugger
.
log
(
"Drawing Canvas"
);
Here is the code for the console.log()
functionality:
var
Debugger
=
function
()
{
};
Debugger
.
log
=
function
(
message
)
{
try
{
console
.
log
(
message
);
}
catch
(
exception
)
{
return
;
}
}
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