Pass an extra argument to a callback function

Question

I have a function callWithMagic which takes a callback function as a parameter and calls it with one argument.

const callWithMagic = callback =&         


        

Answer 1

Just create a wrapper callback:

callWithMagic(function(magic) {
  return processMagic(magic, 42);
});

Or using ECMAScript 6 arrow functions:

callWithMagic(magic => processMagic(magic, 42));