jQuery each() 闭包 - 如何访问外部变量
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jQuery each() closure - how to access outside variable
提问by chris_mac
What's the best way to access my this.rules variable from within $.each()? Any explanation of why/how would also be helpful!
从 $.each() 中访问我的 this.rules 变量的最佳方式是什么？任何关于原因/方式的解释也会有帮助！
app.Style = function(node) {
this.style = node;
this.rules = [];
var ruleHolder = node.find('Rule');
$.each(ruleHolder, function(index, value) {
var myRule = new app.Rule($(ruleHolder[index]));
this.rules.push(myRule);
});
console.log(this.rules)
}
回答by Jo?o Silva
Store a reference to this-- name it self, for example --, before calling .each(), and then access rulesusing self.rules:
在调用之前存储对this- 命名self，例如 - 的引用.each()，然后rules使用self.rules：
app.Style = function(node) {
this.style = node;
this.rules = [];
var ruleHolder = node.find('Rule');
var self = this;
$.each(ruleHolder, function(index, value) {
var myRule = new app.Rule($(ruleHolder[index]));
self.rules.push(myRule);
});
console.log(this.rules)
}
回答by Dustin Page
The answer above by Jo?o Silva is not a good solution as it creates a global variable. You are not actually passing a "self" variable to the each function by reference, but are instead referencing the global "self" object.
Jo?o Silva 上面的答案不是一个好的解决方案，因为它创建了一个全局变量。您实际上并不是通过引用将“self”变量传递给每个函数，而是引用全局“self”对象。
In the example above "this" is the window object and setting "var self = this" isn't really doing anything.
在上面的例子中，“this”是窗口对象，设置“var self = this”并没有真正做任何事情。
The Window object has two self-referential properties, window and self. You can use either global variable to refer directly to the Window object.
Window 对象有两个自引用属性，window 和 self。您可以使用任一全局变量直接引用 Window 对象。
In short, both window and self are references to the Window object, which is the global object of client-side javascript.
总之，window和self都是对Window对象的引用，Window对象是客户端javascript的全局对象。
Creating a closure function is a better solution.
回答by Zoltán Süle
it is more elegant without var self = this;
没有它更优雅 var self = this;
app.Style = function(node) {
this.style = node;
this.rules = [];
var ruleHolder = node.find('Rule');
$.each(ruleHolder, function(index, value) {
var myRule = new app.Rule($(ruleHolder[index]));
this.rules.push(myRule);
}.bind(this));
console.log(this.rules)
}
