I have a main function in javascript that is function a() { some code here } and I also have a child function in this main function that looks like
function a() {
function b() {
// some code here
}
}
now I want to call the function b directly. then how to do this.
You can't. You can, however do something like:
function a() {
this.b = function () {
some code here
}
}
And then call it like:
var x = new a();
a.b();
You can also create an object literal with your function:
var a = {
b: function ()
{
//some code here
}
};
And then just say:
a.b();
You could also create a property on the function object itself, and access it that way:
function a()
{
};
a.b = function ()
{
//Some code here
};
And then call it with:
a.b();
You could try explicitly exposing b to the global object like this:
function a() {
function b() {
// some code here
}
window.exposed = b;
}
Don't declare function b inside of function a, just call it like so
function b() {
some code here
}
function a() {
b();
}
a from b i.e. how to hoist out the locals of a to make the closures equivalent.There are many solutions here, the only one I think that will suit is to attach the function to the global object so it looks like a declared function. The only difference is that it won't be available until a runs:
function a() {
// Protect against ES5 strict mode, assume function is called as global code
if (typeof this !== undefined) {
this.b = function() { /* whatever */ };
}
}
or perhaps the following suits your coding style better:
function a() {
function b() { /* whatever */};
if (typeof this !== undefined) {
this.b = b;
}
}
Called simply as:
a();
then in ES3 or ES5 non-strict mode, it will work as expected. To overcome ES5 strict limitations where the above will result in a's this being undefined, call a as global code and set its this explicitly:
a.call(this);
or with some other suitable reference to the global object.
I have stayed away from using window since that is less reliable, not least because non–browser hosts will likely not have a window object.
