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Andrew Whatmore
Full Stack JavaScript Techdegree Student 13,175 PointsJavaScript passing in copies of variables to functions
Since JavaScript passes in copies of variables as the arguments in function calls, does this make the use of recursion space-expensive, since new copies are made on each recursive call?
1 Answer
Laura Coronel
Treehouse TeacherHi Andrew Whatmore Great question! You're right that each recursive call creates a new stack frame, which takes up memory. However, JavaScript doesn't necessarily copy the entire value of every argument.
For primitive values (like numbers and strings), the value is passed to the function. For objects and arrays, the reference is copied, not the entire object or array.
Recursion does have some memory overhead because each call stays on the call stack until it returns. So, deep recursion can use a lot of memory and may eventually cause a stack overflow. The amount of memory used depends on how many recursive calls are active and what each call needs to keep track of.