finally

practical-curry.js

const a = [1,2,3,4];
const checkType = (type, collection2check) => collection2check.every((each) => typeof each === type); 
const curr = (collection) => {
  return (actionOrType, actionFn) => {
    return actionFn(actionOrType, collection) ? `all in ${collection} are ${actionOrType}s` : `few or none in ${collection} are ${actionOrType}s`;
  };
}

const arr = curr(a);
console.log(arr('number', checkType))
console.log(arr('string', checkType))
console.log(curr(a)('string', checkType))