Does javascript offer updatable parameters

[cupboy]

When calling a function can a parameter be updated? I tried adding the word ref in front, but Javascript didnt like that idea. I also tried an ampersand. Is it just not possible to update a parameter in a function with Javascript?

[JPnyc]

if the parameteris being passed as an argument yes, or if it's a global variable, you can actually set the value in the function call as well.