Java Reference
In-Depth Information
An example of a mistake that causes a warning is assigning a value to a variable that's un-
declared:
pi = 3.142;
<< JavaScript Warning: assignment to undeclared variable
Warnings and exceptions are presented differently in various browser environments. Some
of them will show a small icon in the corner of the browser window to indicate that an ex-
ception or warning has occurred, whereas others require the console to be open to see any
warnings or exceptions.
When an exception occurs, the HTML will still appear but the JavaScript code will stop
working, which isn't always obvious. If a warning occurs, the JavaScript will continue to
run (although possibly incorrectly).
