Javascript命名空间 - 如何根据命名导出函数范围内定义的函数和变量？

Question

使用下面的代码,除了手动指定之外,有没有办法只导出名称不以下划线开头的函数和变量？

var myapp = myapp || {};
myapp.utils = (function() {
  var
    CONSTANT_A = "FOO",
    CONSTANT_B = "BAR";

  function func() {}
  function _privateFunc() {}

  return {//return all variables and functions whose name does not have the "_" prefix.}
}());

Answer 1

您的想法需要能够列出本地范围内的所有变量.不幸的是,JavaScript无法做到这一点.看到这个相关的问题.

我已经看到过两种方法:

1)将每个变量定义到要导出的对象时附加:

var myapp = myapp || {};
myapp.utils = (function () {
    var exports = {};

    exports.CONSTANT_A = "FOO",
    exports.CONSTANT_B = "BAR";

    exports.func = function func() {}

    function _privateFunc() {}

    return exports;
}());

2)或者在对象文字中列出最后的所有导出:

var myapp = myapp || {};
myapp.utils = (function () {
    var 
       CONSTANT_A = "FOO",
       CONSTANT_B = "BAR";

    function func() {}
    function _privateFunc() {}

    return {
        CONSTANT_A: CONSTANT_A,
        CONSTANT_B: CONSTANT_B,
        func: func
    };
}());

我已经看到了两种(甚至是两种混合物)在实践中使用过.第二个看起来可能更迂腐,但也允许读者查看单个代码段并查看该函数返回的整个界面.