Update Higher-order-functions.md

alexpaul · web-flow · commit bed1379dbf95 · 2020-10-25T16:51:15.000-04:00
diff --git a/Higher-order-functions.md b/Higher-order-functions.md
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 # Higher order functions 
 
+A higher-order function is a function that takes in another function or returns a function. Such functions include `map` and `filter`. 
+
 ## Re-creating the built-in `map` function
 
 Custom map
