[英]javascript anonymous function with access to variable in creator
I need to access the i
variable from the loop, in the success function. 我需要在成功函数中从循环访问
i
变量。 How do I do that?, can I pass it in to the function? 我该怎么做?我可以将其传递给函数吗?
function save(){
var mods=model.things;
for (i in mods) {
var mod= mods[i];
$.ajax({
url: "duck"
type: "put",
data: JSON.stringify(mod),
success: function(responce_json) {
var j=i;
}
});
}
}
One way: 单程:
success: (function(i) { return function(responce_json) {
var j=i;
}})(i)
This uses an Immediately Invoked Function Expression (IIFE) to create a closure that will capture the current value of i
. 这使用立即调用函数表达式(IIFE)创建一个闭包,该闭包将捕获
i
的当前值。
Incidently, for...in
is considered bad practice by a lot of JavaScript programmers , but if you need to use it, you should probably at least include a check for hasOwnProperty
顺便说一下,
for...in
,许多JavaScript程序员都认为这是不好的作法,但如果您需要使用它,则可能至少应包括对hasOwnProperty
的检查
Create another function
that takes i
as a parameter thus creating a local copy for each iteration 创建另一个将
i
作为参数的function
,从而为每次迭代创建一个本地副本
var f = function(i) {
var mod= mods[i];
$.ajax({
url: "duck"
type: "put",
data: JSON.stringify(mod),
success: function(responce_json) {
var j=i;
}
});
}
for (iter in mods) {
f(iter);
}
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