{"json_modified": "2016-10-13T02:02:08.842035", "uuid": "190868cf-8ae4-4d6d-9114-dc118e558020", "title": "Functions \u2014 reusable blocks of code", "url": "/en-US/docs/Learn/JavaScript/Building_blocks/Functions", "tags": ["anonymous", "API", "invoke", "Functions", "Browser", "Guide", "Learn", "Article", "CodingScripting", "parameters", "Custom", "JavaScript", "Method", "Beginner"], "translations": [], "modified": "2016-10-13T02:02:08", "label": "Functions \u2014 reusable blocks of code", "localization_tags": [], "locale": "en-US", "id": 192859, "last_edit": "2016-10-13T02:02:04", "summary": "Another essential concept in coding is <strong>functions</strong>, which allow you to store a piece of code that does a single task inside a defined block, and then call that code whenever you need it using a single short command \u2014 rather than having to type out the same code multiple times. In this article we'll explore fundamental concepts behind functions such as basic syntax, how to invoke and define them, scope, and parameters.", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Where_do_I_find_functions", "title": "Where do I find functions?"}, {"id": "Built-in_browser_functions", "title": "Built-in browser functions"}, {"id": "Functions_versus_methods", "title": "Functions versus methods"}, {"id": "Custom_functions", "title": "Custom functions"}, {"id": "Invoking_functions", "title": "Invoking functions"}, {"id": "Anonymous_functions", "title": "Anonymous functions"}, {"id": "Function_parameters", "title": "Function parameters"}, {"id": "Function_scope_and_conflicts", "title": "Function scope and conflicts"}, {"id": "Active_learning_Playing_with_scope", "title": "Active learning: Playing with scope"}, {"id": "Functions_inside_functions", "title": "Functions inside functions"}, {"id": "Conclusion", "title": "Conclusion"}, {"id": "See_also", "title": "See also"}], "slug": "Learn/JavaScript/Building_blocks/Functions", "review_tags": []}