Higher order functions in JavaScript:

o   Higher Order Functions are functions that perform operations on other functions.

o   Higher-order functions are functions that make use of functions as either their argument or their return value.

o   Functions that get passed in as parameters are callback functions.

o   Functions can be passed into other functions as arguments.

o   In JavaScript functions, map, filter and reduce are examples of built-in higher-order functions. 

 EXAMPLE:

Higher-order function that accepts another function as an argument:

 OUTPUT:

 Higher-order function that returns a function: 

OUTPUT: