Function Junction

Question 1

Short def. of a closure

Answer 1

Function that returns references to objects from its local scope.
- Typically returns an IIF

Question 2

T/F: A method’s context (this) is bound to the object that it is a method of

Answer 2

False. A calling function can give ‘function context’ to a method.

Question 3

Another name for ‘context’ in javascript

Answer 3

“This” = context

Question 4

How is ‘this’ defined in strict mode?

Answer 4

Strict mode requires an assigned context, or ‘this’ is undefined. It does not default to global object.

Question 5

Function w/ Call – what’s happening?

myFunction.call(x, 1,2)

Answer 5

myFunction will be executed with the properties of ‘x’ and other given parameters

Question 6

Function w/ Apply – what’s happening?

myFunction.apply(x, [1,2])

Answer 6

this = ‘x’ and the rest of the parameters are given in an array
* Use if the other parameters you wanted to send were already in an array?

Question 7

What is the syntax diff between declaring a function and invoking a function?

Answer 7

Declaration: uses function keyword to define a function

Invoking: uses ( ); and returns a value

Question 8

What is a function expression? Why is this a significant distinction?

Answer 8

A function assigned to a variable, not defined with formal function definition.
+ Allows reassignment of variable
+ Assigned function can be anonymous
+ Function expressions are not hoisted b/c they follow variable scope rules

Question 9

How do you invoke an anonymous function?

Answer 9

Assign to variable (create function expression) and call with variable name
- End with semi-colon to execute

Question 10

Syntax for a self-invoking function

Answer 10

Entire function wrapped in ( ),followed by ( );
* Cannot be used on function declaration

(function( ){ …stuff…})( );