I'm using CodeLite 9.02 under Linux-Ubuntu 15.10. Define this object:

var debuggerTestObject = {
    firstBoolean : true,
    secondBoolean : true,
    thirdBoolean: false,
    fourthBoolean: false,
    firstInt: 42,
    secondInt: 43,
    thirdInt: 42,
    fourthInt: 43
};

Then add a line where you can set a breakpoint and watch the object debuggerTestObject, like this:

console.log(debuggerTestObject.firstBoolean);

The debugger (both debugger pane and mouseover pop-up window) will show the following members for the object:

firstBoolean = true,
thirdBoolean = false,
firstInt = 42,
secondInt = 43,

What's happening here is that those object members that were intialized to the same value as a previous member are ignored by the debugger. If you change the value of an ignored member later to some other value that is not in use, that member will show up. For example:

debuggerTestObject.thirdInt = 44;
console.log(debuggerTestObject.thirdInt);

Now the member thirdInt will show up in the debugger.

This behavior is happens not only for object literals, but also for objects created with new.