使用命名函数进行回调 [英] Using named functions for callbacks

问题描述

我在使用匿名函数对javascript进行性能分析时遇到了一个主要问题，我总是有很多匿名函数-其中大多数是回调函数-这使我很难分析探查器的结果.

I have a major problem with profiling in javascript with anonymous functions, I have always many anonymous functions - most of them are callbacks - and It makes analyzing results of profiler very hard for me.

最后，我决定使用命名函数进行回调，如下所示:

Finally I decided to use named functions for callbacks, like this:

var f = function(callback) {
    // Do something ...
    callback();
}

f(function named_function() {
    console.log('Sample callback function!');
});

我想知道在对代码进行此更改后是否会有任何问题?这种类型的函数定义和传递会在任何地方保留名称(named_function)吗?

I want to know that will I have any problems after making this change in my codes? And will this type of function definition and passing reserve the name (named_function) anywhere?

推荐答案

该名称仅在命名函数表达式的范围内可用.

The name will only be available inside the scope of the named function expression.

但是在IE 8及更低版本中存在问题.它会泄漏到外部范围，并实际上会创建一个不同的函数对象，因此如果出现问题，则应将其无效.

But there is a problem in IE 8 and lower. It will leak out to the outer scope, and will actually create a different function object, so you should nullify it if that's a problem.

f(function named_function() {
    console.log('Sample callback function!');
});
var named_function = null;

有关更多信息，请参见本文:已解密的命名函数表达式

See this article for more information: Named function expressions demystified

或者您可以像这样创建它来解决IE问题.

Or you could create it like this to solve the IE issue.

f(function() {
    return function named_function() {
        console.log('Sample callback function!');
    };
}());

但这有点丑陋.

这篇关于使用命名函数进行回调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！