Does Javascript allocate 32 bits of memory for variables with an undefined value?

Question

Suppose I have the following function signature:

function test(varible1, varible2) {}

When I call it I pass only one parameter:

test(5);

So within test function the variable2 still be created but will have value of undefined. I'm wondering if js engine still allocates 32 bit in the memory for that variable?

Answer 1

I can't find the size of undefined and I'm sure it varies with engine, but I assume that the best case is 32 bits. The variable exists, so it needs a value to even know it's undefined. That value is very likely a pointer which will be 32 or 64 bits.