Currying Variations

Type 1

const sum = (a) => (b) => b ? sum2(a + b) : a
console.log(sum(1)(2)(3)());  //6

Type 2

const sum = (a, b, c) => a + b + c

const curry = (fn) => {
  return function curried(...args) {
    return args.length >= fn.length
      ? fn(...args)
      : (...newArgs) => curried(...args, ...newArgs)
  }
}

const curriedSum = curry(sum);
console.log(curriedSum(1)(2)(3)); // 6

Type 3

const add = (...args) => args.reduce((acc, curr) => acc + curr, 0);

const sum = (...args) => {
  // Initialize total sum with the provided arguments
  let total = add(...args);

  // Helper function to accumulate sums
  const helper = (...newArgs) => {
    if (newArgs.length === 0) {
      // If no new arguments are provided, return the total sum
      return total;
    }
    // Update the total with new arguments and return the helper function for further chaining
    total += add(...newArgs);
    return helper;
  };

  return args.length === 0 ? 0 : helper;
};

// Example usage
console.log(sum(1)(2)(3)()); // 6
console.log(sum(1, 2)(3)()); // 6
console.log(sum(1)(2, 3)()); // 6
console.log(sum(1, 2, 3, 4)()); // 10
console.log(sum(1)(2, 3, 4)()); // 10
console.log(sum()); // 0