JSON Issues in XPages - Unknown literal of class com.ibm.jscript.types.FBSUndefined

This post does not speak about any fixes for this error message, however, contains a tip that will help avoid the issue.

I encountered this error when I tried to apply toJson method on a json construct.

I had the following json construct. Let me say this as "x"

{"menuItems": [
{
"serialNumber": 1,
"Label": "Label_1",
"Link":"Link_1",
"subMenuItems": [
{
"serialNumber": 1,
"Label": "Label_1",
"Link":"Link_1",
"subMenuItems": [
,
]
},

]
},
]}

When i attempted some thing like toJson(x), I got the FBSUndefined error. How ever, when I attempted, fromJson(x) I got sort of I got the following error

Error when parsing JSON string
Encountered " "object "" at line 1, column 2. Was expecting one of: "false" ... "null" ... "true" ...blah blah blah

When I just put my json construct on to a field's default value and tried to parse the field's value using the following code

x=getComponent("toJsonTest").getValue();

y=fromJson(x);

getComponent("result").setValue(y.menuItems.length)//-> result was 2.0 (i guess)

it worked like charm. Voila

I understand that this must be sort of, a beginner level stuff for Json in XPages.
If you would like to be saddened further by coding a lot to obtain perfection, may be you can explore "com.ibm.commons.util.io.json" and use them in your SSJS :P