For example, I have an array of functions:
[func1, func2, func3, func4] and array of arguments [arg1, arg2, arg3, arg4]. I need to apply func1 to arg1, func2 to arg2 etc.
What is the best way to do this? Of course, I can use simple loop to go through elements, but maybe more elegant way exists.
There are a few ways to do it. I'd suggest using the .map() method to iterate over the functions, because then you can easily put their return values into another array:
const results = funcs.map((f, i) => f(args[i]))
In context:
const funcs = [
(a) => a * 2,
(a) => a * 3,
(a) => a * 4,
(a) => a * 5
]
const args = [1, 2, 3, 4]
const results = funcs.map((f, i) => f(args[i]))
console.log(results)I don't know if it's "elegant," but you can do
let results = functionArray.map((f, i) => f(arguments[i]))
This takes each function in your array, finds the associated argument i, and calls the function with that argument.
If you use a library like Lodash, you can use _.zipWith, which iterates several arrays at once all in parallel, calling the provided function with the elements of the arrays.
const results = _.zipWith(funcs, args, (f, a) => f(a));
If you want a simple implementation of zipWith without importing the library, use:
const zipWith = (...arrays) => {
const func = arrays.pop();
return arrays[0].map((_, i) => func(...arrays.map(arr => arr[i])));
};
const zipWith = (...arrays) => {
const func = arrays.pop();
return arrays[0].map((_, i) => func(...arrays.map(arr => arr[i])));
};
const funcs = [
a => a * 2,
a => a * 3,
a => a * 4,
a => a * 5
];
const args = [1, 2, 3, 4];
console.log(zipWith(funcs, args, (f, a) => f(a)));