Calling javascript function with an objectstring in dot notation
Suppose I have the string:
var string = "function";
With
window[string];
I can call a function with the name of "function".
But, when I have:
var string2 = "function.method.weHaveTogoDeeper";
it should call
window["function"]["met开发者_如何转开发hod"]["weHaveTogoDeeper"]
I can't do:
window[string2]
in this case. I dont know the number of "." in the string, so I need some kind of routine.
you can split the string across .
by using the String.split
method:
var string2 = "function.method.weHaveTogoDeeper";
var methods = string2.split(".");
In this examples, methods
will be the array ["function","method","weHaveTogoDeeper"]
. You should now be able to do a simple iteration over this array, calling each function on the result of the previous one.
Edit
The iteration I had in mind was something like this:
var result = window;
for(var i in methods) {
result = result[methods[i]];
}
In your example, result
should now hold the same output as
window["function"]["method"]["weHaveTogoDeeper"]
function index(x,i) {return x[i]}
string2.split('.').reduce(index, window);
edit: Of course if you are calling functions from strings of their names, you are likely doing something inelegant which would be frowned upon, especially in a collaborative coding settings. The only use case I can think of that is sane is writing a testing framework, though there are probably a few more cases. So please use caution when following this answer; one should instead use arrays, or ideally direct references.
I wrote one a while back:
function RecursiveMapper(handlerName, stack) {
// check if empty string
if(!handlerName || handlerName === '' || (handlerName.replace(/\s/g,'') === '')) return null;
var buf = handlerName.split('.');
stack = stack || window;
return (buf.length === 1) ? stack[buf[0]] : this.RecursiveMapper(buf.slice(1).join('.'), stack[buf[0]]);
}
Call it like this: RecursiveMapper(window[string2]);
This one also checks if the function is defined in window
scope first and returns the global one fi found.
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