Bind specific arguments of a function
To bind specific (nth) arguments of a function, we can write a decorator instead of using Function.bind():
function func(p1, p2, p3) {
console.log(p1, p2, p3);
}
// the binding starts after however many are passed in.
function decorator(...bound_args) {
return function(...args) {
return func(...args, ...bound_args);
};
}
// bind the last parameter
let f = decorator("3");
f("a", "b"); // a b 3
// bind the last two parameter
let f2 = decorator("2", "3")
f2("a"); // a 2 3
Even if we want to bind just the nth argument, we can do as follows:
// bind a specific (nth) argument
function decoratorN(n, bound_arg) {
return function(...args) {
args[n-1] = bound_arg;
return func(...args);
}
}
let fN = decoratorN(2, "2");
fN("a","b","c"); // a 2 c