$范围和$ rootscope混乱 [英] $scope and $rootscope confusion

问题描述

我不明白为什么这个程序的输出并不是

I don't understand why the output of this program is not

Global value is 4 

Child Instance of Function1 created :- 1

Child Instance of Function2 created :- 2

Child Instance of Function1 created :- 3

Child Instance of Function2 created :- 4

Plunker - http://plnkr.co/edit/HktvgxMM0g1WJG2oLjIN?p=preVIEW

感谢您的帮助。

推荐答案

您可以用这种方式$ rootScope明白这是最上面的范围，所有其他范围（即$范围内）来这里面。所以，柜面你必须通过范围之间的值，那么你必须使用$ rootScope。

You can understand it in this way $rootScope is top most scope and all the other scope (i.e. $scope) comes inside this. So incase you have to pass value between scope then you have to use $rootScope.

请注意：功能1使用局部变量柜台里范围在控制器内。即每个控制器，有自己的范围。功能2使用全局变量计数器，因为没有全局变量定义。

Note: function1 use local variable Counter where scope is within the controller. I.e. each controller have there own scope. function2 use global variable Counter, because no global variable define.

在你的情况下，（记住角度支持双向绑定，所以每当全球价值改变它在所有的地方的变化），控制器被调用的顺序如下功能1 - >功能2 - >功能1 - >功能2

In your case the (remember angular support two way binding, so whenever global value change it changes at all the places), The controllers get called in following order function1 -> function2 -> function1 -> function2.

在功能1 获得所谓的第一次 $ rootScope.Counter 不是present所以它具有一个初始化和分配相同的局部变量计数器。

When function1 get called first time $rootScope.Counter is not present so it initialize with one and assign the same to local variable 'Counter'.

so output look like
Global value is 1 
Child Instance of Function1 created :- 1

Child Instance of Function2 created :- 1

Child Instance of Function1 created :- NA // local scope for this is not created

Child Instance of Function2 created :- 1

现在函数2将被调用。这种增加全局变量计数器为2，并用它来显示

Now function2 will get called. This increase global variable Counter to 2 and use it to display

so output look like
Global value is 2 
Child Instance of Function1 created :- 1

Child Instance of Function2 created :- 2

Child Instance of Function1 created :- NA // local scope for this is not created

Child Instance of Function2 created :- 2

现在FUNCTION1将再次调用。这一增长全局变量计数为3，并为其分配局部变量。

Now function1 will get called again. This increase global variable Counter to 3 and assign it local variable.

so output look like
Global value is 3 
Child Instance of Function1 created :- 1

Child Instance of Function2 created :- 3

Child Instance of Function1 created :- 3 //Because rootScope already have counter variable with 2

Child Instance of Function2 created :- 3

终于函数2再次调用，这增加了全局变量计数为4，并用它来显示

and finally function2 get called again, This increase global variable Counter to 4 and use it to display

so output look like
Global value is 4 
Child Instance of Function1 created :- 1

Child Instance of Function2 created :- 4

Child Instance of Function1 created :- 3

Child Instance of Function2 created :- 4

这篇关于$范围和$ rootscope混乱的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！