Javascript Closures
Popularity Report
 |
|||
|
|||
|
|||
|
|||
|
|||
|
Rank
URL Tag Cloud
Bookmark History
Saved by 37 people (-10 private), first by anonymouse user on 2006-08-03
- Rune66 on 2009-06-13 - Tags javascript , closures
- Bagulin_l on 2009-05-12 - Tags javascript , closures , замыкания
- Sbelur on 2009-04-28 - Tags javascript
- Shengyan on 2009-02-23 - Tags javascript , webdev , programming
- Hariprasade on 2009-02-17 - Tags closures , computr_science , javascript , languages
Public Sticky notes
The simple explanation of a Closure is that ECMAScript allows inner
functions; function definitions and function expressions that are
inside the function bodes of other functions. And that those inner
functions are allowed access to all of the local variables, parameters
and declared inner functions within their outer function(s). A closure
is formed when one of those inner functions is made accessible outside
of the function in which it was contained, so that it may be executed
after the outer function has returned. At which point it still has
access to the local variables, parameters and inner function
declarations of its outer function. Those local variables, parameter
and function declarations (initially) have the values that they had
when the outer function returned and may be interacted with by the
inner function.
Highlighted by keikozhou
The simple explanation of a Closure is that ECMAScript allows inner
functions; function definitions and function expressions that are
inside the function bodes of other functions. And that those inner
functions are allowed access to all of the local variables, parameters
and declared inner functions within their outer function(s).
Highlighted by keikozhou
If a value is assigned
and the actual object does not have a property with the corresponding
name a property of that name is created and the value is assigned to
it. If it has the property then its value is re-set.
Highlighted by hariprasade
If a value is assigned
and the actual object does not have a property with the corresponding
name a property of that name is created and the value is assigned to
it. If it has the property then its value is re-set.
Highlighted by navneetk
all objects may have prototypes, and prototypes are objects so they, in
turn, may have prototypes, which may have prototypes, and so on forming
what is called the prototype chain. The prototype chain ends when one
of the objects in the chain has a null prototype. The default prototype for the
Object constructor has a null prototype so
Highlighted by navneetk
all objects may have prototypes, and prototypes are objects so they, in
turn, may have prototypes, which may have prototypes, and so on forming
what is called the prototype chain. The prototype chain ends when one
of the objects in the chain has a null prototype. The default prototype for the
Object constructor has a null prototype so
Highlighted by hariprasade
When a javascript function is called it enters an execution context,
if another function is called (or the same function recursively) a new
execution context is created and execution enters that context for the
duration of the function call. Returning to the original execution
context when that called function returns. Thus running javascript code
forms a stack of execution contexts
Highlighted by hariprasade
When a javascript function is called it enters an execution context,
if another function is called (or the same function recursively) a new
execution context is created and execution enters that context for the
duration of the function call. Returning to the original execution
context when that called function returns. Thus running javascript code
forms a stack of execution contexts
Highlighted by navneetk
First, in the execution context of a function, an
"Activation" object is created.
Highlighted by hariprasade
First, in the execution context of a function, an
"Activation" object is created.
Highlighted by navneetk
The next step in the creation of the execution context for a function
call is the creation of an
arguments object, which is an
array-like object with integer indexed members corresponding with the
arguments passed to the function call, in order.
Highlighted by hariprasade
The next step in the creation of the execution context for a function
call is the creation of an
arguments object, which is an
array-like object with integer indexed members corresponding with the
arguments passed to the function call, in order.
Highlighted by navneetk
Next the execution context is assigned a scope. A scope consists of a
list (or chain) of objects.
Highlighted by hariprasade
Next the execution context is assigned a scope. A scope consists of a
list (or chain) of objects.
Highlighted by navneetk
the Activation object is used as the Variable object (note this, it is
important: they are the same object). Named properties of the Variable
object are created for each of the function's formal parameters, and if
arguments to the function call correspond with those parameters the
values of those arguments are assigned to the properties (otherwise the
assigned value is
undefined)
Highlighted by hariprasade
the Activation object is used as the Variable object (note this, it is
important: they are the same object). Named properties of the Variable
object are created for each of the function's formal parameters, and if
arguments to the function call correspond with those parameters the
values of those arguments are assigned to the properties (otherwise the
assigned value is
undefined)
Highlighted by navneetk
It is the fact that the Activation object, with its
arguments property, and the Variable object, with named
properties corresponding with function local variables, are the same
object, that allows the identifier arguments to be treated
as if it was a function local variable.
Highlighted by navneetk
It is the fact that the Activation object, with its
arguments property, and the Variable object, with named
properties corresponding with function local variables, are the same
object, that allows the identifier arguments to be treated
as if it was a function local variable.
Highlighted by hariprasade
Public Comment