JS Closures

by Kim Maida March 28, 2017

JavaScript

function whenMeetingJohn(salutation) {
  var greeting = salutation + ', John!';
  
  function alertGreeting() {
    alert(greeting);
  }
  return alertGreeting;
}
var atLunchToday = whenMeetingJohn('Hi');

atLunchToday(); // alerts "Hi, John!"
whenMeetingJohn('Whassup')(); // alerts "Whassup, John!"

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JS Closures

JavaScript

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Join the 4+ million users, and keep the JSFiddle dream alive.

Ad-free

Use pre-released features

Fiddle collections

Private collections and fiddles

Console