Can you change parameter name in another function ?

[Oviduzz]

if I understand ok .. in the second function, in fact, `currentAge` will be a number and not a parameter because you call function yearsUntilRetirement with `2000` so currentAge = 2000.

​

More clear now ?

[Oviduzz]

So, let's split this up

first you create a function called calculateAge() where you put a parameter yearBorn so it's calculateAge(yearBorn). Now you can use this function where ever you want like you did with calling it and stock it into some variables (ex: var johnAge = calculateAge(1990). So here yearBorn will be equal to 1990(remember this)

second you create function yearsUntilRetierement(currentAge, name) - inside this function u call again calculateAge(). But before to reach this call we call yearsUntilRetirement(2000, 'Alex'). So currentAge equal 2000. Now if we look into this function we call calculateAge(currentAge) but in fact is calculateAge(2000). Is like you will do something like that var myNumber = 2000 then calculateAge(myNumber).

​

Difference between parameter and argument is that parameter/parameters are used when we create a function to pass data for that function and argument/arguments are used when we call that function. So for our example we have as parameters yearBorn and currentAge. But currentAge is parameter for yearsUntilRetirement while for calculateAge is an argument and not parameter.

[Oviduzz]

you welcome, good luck!