What do parentheses surrounding an object/function/class declaration mean? [duplicate]

by

It is a self-executing anonymous function. The first set of parentheses contain the expressions to be executed, and the second set of parentheses executes those expressions.

It is a useful construct when trying to hide variables from the parent namespace. All the code within the function is contained in the private scope of the function, meaning it can’t be accessed at all from outside the function, making it truly private.

See:

http://en.wikipedia.org/wiki/Closure_%28computer_science%29

http://peter.michaux.ca/articles/javascript-namespacing

More Related Contents:

  1. var functionName = function() {} vs function functionName() {}
  2. JavaScript property access: dot notation vs. brackets?
  3. Explain the encapsulated anonymous function syntax
  4. Question mark and colon in JavaScript
  5. Why does ++[[]][+[]]+[+[]] return the string “10”?
  6. What does a tilde do when it precedes an expression?
  7. What does the plus sign do in ‘+new Date’
  8. Convert string in dot notation to get the object reference [duplicate]
  9. How can I refer to a variable using a string containing its name?
  10. Why should I use a semicolon after every function in javascript?
  11. Difference between using bracket (`[]`) and dot (`.`) notation [duplicate]
  12. Is localStorage.getItem(‘item’) better than localStorage.item or localStorage[‘item’]?
  13. Double quotes within php script echo
  14. Advanced JavaScript: Why is this function wrapped in parentheses? [duplicate]
  15. difference between dot notation and bracket notation in javascript [duplicate]
  16. Dot and Square Bracket Notation
  17. Use a concatenated (dynamic) string as JavaScript object key? [duplicate]
  18. Syntax highlighting code with Javascript [closed]
  19. Why does 10..toString() work, but 10.toString() does not? [duplicate]
  20. Difference between var and this in Javascript functions?
  21. syntax error: unexpected token
  22. “elseif” syntax in JavaScript
  23. What is the purpose of a semicolon before an IIFE? [duplicate]
  24. JSON syntax for property names
  25. Does assignment with a comma work?
  26. javascript syntax: function calls and using parenthesis
  27. JavaScript dot notation [duplicate]
  28. What’s the reason for using such syntax (0, _.Em)();
  29. Javascript history.PushState not working?
  30. + operator before expression in javascript: what does it do?

Leave a Comment