Passing a function as a parameter to another function

The function hi is a function that has a single parameter -- a function. The function displays 'hi' according to the specified outputFunction that is passed to the function hi.

  
   function hi(outputFunction) {
      let x = 'hi'
      outputFunction(x);
    }  
  

• Clicking the Default Alert button calls hi(alert)
• Clicking the Print to Console button calls hi(console.log)
• Clicking the My Alert button calls hi(myAlert), where myAlert is a user-defined function

Anonymous functions

An anonymous function is a function that does not have a name

• Clicking the Anonymous Hi button calls AnonymousHi which uses an anonymous function:

       hi(function(x) {
          alert('anonymous alert says: ' + x);
        });
      

  Note that this is equivalent to hi(myFunction), where

       myFunction = function(x) {
          alert('anonymous alert says: ' + x);
       }