undefined is a property of the global object. That is, it is a variable in global scope. The initial value of undefined is the primitive value undefined.
A variable is ‘declared’, it has its own placeholder (memory is allcoated) but not having the value of itself ‘defined’ hence ‘undefined’. Until the variable has assigned a value, the ‘undefined’ fills that particular placeholder and ‘undefined’ is itself a datatype.
This case comes in error where js engine neither find that particular variable nor its placeholder and cannot find the variable in 1st phase of context (Memory allocation context)
Use the share button below if you liked it.
It makes me smile, when I see it.