generics<T>.ts

function myForEach<T>(arr: T[], forEachFunc: (v: T) => void) {
  arr.reduce((acc, val) => {
    forEachFunc(val)
    return undefined;
  }, undefined)
}
  
function myFilter<T> (arr: T[], filterFunc: (v: T) => boolean): T[] {
  return arr.reduce((acc: T[], val) => {
    if (filterFunc(val)) {
      return [...acc, val]
    } else {
      return [...acc]
    }
  }, [])
}
  
function myMap<T, K>(arr: T[], mapFunc: (v: T) => K) {
  return arr.reduce((acc: K[], curr) => [...acc, mapFunc(curr)], [])
}