Scatter debug messages throughout your code to provide a high-level overview of what your code is doing, such as which function is currently in scope and the values of loop counters.
Information messages are the meat and potatoes of logging messages; sprinkle them around to reveal more detailed information about your script's execution, such as the values of variables and function/method return values.
Warning messages are used to indicate potentially hazardous situations, such as missing function arguments...
While error messages are used to indicate that something bad is about to happen; note that these kinds of errors are considered to be run-time errors, which are a different type of beast from the parse errors mentioned below.
Error on line 157 of document https://zanstra.com/arc/xs4all/dzLib/fvlogger/logger.js: Uncaught ReferenceError: a is not defined
var s='hoi';
'hoi'
(string)var n=12;
12
(number, int)var n=12.123;
12.123
(number, float)var b=true;
true
(boolean)var u;
not initialized
(undefined)var N=null;
null
(Object)var dt=new Date(2005,11-1,17,23,31,45,100);
2005-11-17T23:31:45.100
(Date)var f=function() { alert('hoi') };
anonymous
(function)var f=function doei() { alert('hoi') };
doei
(function)var r=/[0-9]{4} ?[a-z]{2}/i;
/[0-9]{4} ?[a-z]{2}/i
(RegExp)var a="A,B,C".split(",");
3
(number)
"A"
(string)
"B"
(string)
"C"
(string)
var o={name:'Doekman',email:'doeke@zanstra.net'};
"Doekman"
(string)
"doeke@zanstra.net"
(string)
var o=new Person('Doekman','doeke@zanstra.net');
"Doekman"
(string)
"doeke@zanstra.net"
(string)