Christin Perry is a freelance writer with a passion for all topics related to health and family. She has been working as a writer for seven years now, and her work has appeared in Parents, The Bump, ...

Create a function that sums two arguments together. If only one argument is provided, then return a function that expects one argument and returns the sum.

‘Higher-order functions’ is a fancy term for functions that take other functions as arguments or that return functions. Very powerful! Last week, I casually dropped the term “higher-order function” ...