angular 表达式 {{::}} 中的两个冒号是什么意思？
What does two colons inside an angular expression {{::}} mean?
有什么区别：
{{::office.name}}
和
{{office.name}}
在 angularJS?
{{::office.name}} 语法是 Angular 的 One-Time 绑定，自版本 1.3
起可用
Here's 一个很好的博客解释它。
One-time binding From Angular Docs.
An expression that starts with :: is considered a one-time expression. One-time expressions will stop recalculating once they are stable, which happens after the first digest if the expression result is a non-undefined value (see value stabilization algorithm below).
在许多情况下，值只需要显示在视图中，永远不会从视图或控制器中更新。但是，如果使用 two-way 绑定，$digest 将检查每个循环中表达式的任何变化，这是没有必要的。在这些情况下，应该在表达式之前使用 ::。如上述声明所述，对于这种情况，这比 two-way 绑定语法更有效。
博客：AngularJS one-time binding syntax from @Todd Motto
In a nut shell, when we declare a value such as {{ ::foo }} inside the DOM, once this value becomes defined, Angular will render it, unbind it from the watchers and thus reduce the volume of bindings inside the $digest loop. Simple!
有什么区别：
{{::office.name}}
和
{{office.name}}
在 angularJS?
{{::office.name}} 语法是 Angular 的 One-Time 绑定，自版本 1.3
起可用
Here's 一个很好的博客解释它。
One-time binding From Angular Docs.
An expression that starts with
::is considered a one-time expression. One-time expressions will stop recalculating once they are stable, which happens after the first digest if the expression result is a non-undefined value (see value stabilization algorithm below).
在许多情况下，值只需要显示在视图中，永远不会从视图或控制器中更新。但是，如果使用 two-way 绑定，$digest 将检查每个循环中表达式的任何变化，这是没有必要的。在这些情况下，应该在表达式之前使用 ::。如上述声明所述，对于这种情况，这比 two-way 绑定语法更有效。
博客：AngularJS one-time binding syntax from @Todd Motto
In a nut shell, when we declare a value such as
{{ ::foo }}inside the DOM, once this value becomes defined, Angular will render it, unbind it from the watchers and thus reduce the volume of bindings inside the$digestloop. Simple!