javascript infinite parameters
Functions can access an array-like object called arguments that contains all the arguments that they received
function print_my_arguments(/**/){
var args = arguments;
for(var i=0; i<args.length; i++){
console.log(args[i]);
}
};
Some important points to note:
- arguments isn't an actual array. You can convert it to an array with the following line:
var args = Array.prototype.slice.call(arguments);
Slice is also useful if you want your array to only contain the non-named arguments that were received:
function foo(first_arg, second_arg /**/){
var variadic_args = Array.prototype.slice.call(arguments, 2);
}
Not every browser can handle an arbitrarily large number of function parameters.
Last time I tested this, in Chrome and IE there was a stackoverflow after some 200.000 arguments.
If your function can receive an arbitrarily large number of arguments,
consider packing all of those arguments in an regular array instead.
Those /**/ comments that appear in the arguments lists for my examples are not mandatory. They are just a coding a convention that I use to mark my variadic functions and differentiate them from regular functions.
// A quick glance would suggest that this function receives no
// parameters but actually it is a variadic function that gets
// its parameters via the `arguments` object.
function foo(){
console.log(arguments.length);
}