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JavaScript

Posted by Kinkaid Nolen
Kinkaid Nolen
4,859 Points

Call Back Confusion

In the first function, callback(name); confuses me. So does this mean the "name" value is only returned when its used in a function? Also how does getUserName(greeting); work exaclty?

function getUserName(callback) { const name = prompt('What is your name?'); callback(name); }

function greeting(name) { alert('Hello, ' + name); }

getUserName(greeting); // a reference to the greeting function is passed to the function

1 Answer

Steven Parker
Steven Parker
231,172 Points
Steven Parker
Steven Parker
231,172 Points

The "callback" is provided as an argument, and "name" is input from the console (by "prompt"). So the code "callback(name)" invokes the function that was passed in, and passes "name" as an argument to it. If that all seems a bit complicated, it really is! But it illustrates a powerful feature of JavaScript that is good to know how to use.

The "name" value is used by the callback function (which is "greeting" in the example), but it is not returned by either function.

Kinkaid Nolen
Kinkaid Nolen
4,859 Points

Gotcha, it' slowly starting to click but I'm getting there thank you!