JavaScript

Mi JavaScripts.

Variables

Declaring variables

For modern JavaScript:

• let to declare a variable in modern JavaScript (ES6 or later)
• const for values that must not change, or that you want to throw an error if they are changed.

For JavaScript before ES6:

• var - to declare a variable in versions of JavaScript before ES6.
  • var variables do not have block scope.
  • They are scoped to the body of the containing function.
  • If var is used outside a function body, it declares a global variable.

Troubleshooting

Problem	Cause	Solution
jQuery can’t find plugins: “TypeError: xxxxx is not a function”	jQuery is being loaded twice.	Remove the second jQuery.