javascript-Scopes and action chains

One

In JS, the function is also an object, all objects, function objects, like other objects, have access through code and a series of properties accessed through the JS engine

Two

Action chain: A collection of objects in scope that determines what data can be accessed by a function

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var test=function ()//block-polar scope
{
if (1+1==2) {
var str= "JS has no block-scoped, so str is callable";
}
Console.log (str);
}
Test (); There is no block scope in JS, so str can be called

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var game=function ()
{
swxf= "I fried chicken like to play";
Console.log (SWXF);
}
Game ();//I like to play with fried chicken
Console.log (SWXF);
I fry chicken like play will find, incredibly also show up. This is because SWXF is a global variable, and after the game () call, you can call around SWXF

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var name= "Wanli"; Global Variables Global scope
var fn=function ()//global scope
{
var age= "male"; Local variables
function game ()//local functions
{
Console.log ("Watch Happiness");
}
}
Console.log (name); Miles

javascript-Scopes and action chains