Examples of using Global object in English and their translations into Vietnamese
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Colloquial
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Ecclesiastic
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Computer
What is the global object?
When calling a function this is referring to the global object.
In browsers, the global object is window.
Maybe you passed a callback to a global object.
Undefined is a property of the global object; i.e., it is a variable in global scope.
This property is set on the global object.
In web pages, the global object is window, so you can set and access global variables using the window. variable syntax.
Otherwise, to the global object.
In the first above example, after the function call returns,the 2 objects are not referenced anymore by something reachable from the global object.
In JavaScript, there's always a global object defined.
In the first example above, after the function call returns, the two objects are nolonger referenced by any resource that is reachable from the global object.
The functionality of namespaces is specially useful in casethat there is a possibility that a global object or function can have the same name than another one, causing a.
With an assignment, without the var statement, if the referenced identifier is not found in the scope chain,it will become a deleteable property of the global object.
I assume that the reader is already familiar with JavaScript,knows what is a Global Object, knows that functions in JavaScript are“first-class objects”, etc.
There are a number ofsituations that could cause this to be bound to the global object.
The global object itself can be accessed using the this operator in the global scope(but only if ECMAScript 5 strict mode is not used; in that case it returns undefined).
If we access bar, we get value 2 from Global object.
One of the properties that we're interested in is an internal property[[scope]]; it refers to the current scope object, that is, the scope object that was active when the function is defined(again,in this case, Global object).
When the function myFunc is defined,myFunc identifier is added to the current scope object(in this case, Global object), and this identifier refers to the function object. .
So, when you define some variables in top-level code,they are defined on Global Object.
For example, if you forget to provide the new prefix when calling a constructor function,the constructor's this will be bound unexpectedly to the global object, so instead of initializing a new object, it will instead be silently tampering with global variables.
The last element in the scope chain is always the Global Object.
In strict mode, when used alone,this also refers to the Global object[object Window].
So by default this refers to the global object.
The window object is also the global object.
As I mentioned above, for top-level code,scope object is a Global Object.
In top-level JavaScript code,scope chain contains just a single element: the Global Object.
Speaking about the global context, both, the var statement anda FunctionDeclaration at the end will create a non-deleteable property on the global object, but the value of both can be overwritten.