You can export multiple functions from a file, no React needed per se:
Helpers.js:
export function plus(a, b) {
return a + b;
}
export function minus(a, b) {
return a - b;
}
export function multiply(a, b) {
return a * b;
}
export function divide(a, b) {
return a / b;
}
You can then import the functions you need:
import { multiply, divide } from './Helpers'