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JavaScript: Uncurry a function up to depth n

JavaScript fundamental (ES6 Syntax): Exercise-114 with Solution

Write a JavaScript program to uncurry a function up to depth n.

  • Return a variadic function.
  • Use Array.prototype.reduce() on the provided arguments to call each subsequent curry level of the function.
  • If the length of the provided arguments is less than n throw an error.
  • Otherwise, call fn with the proper amount of arguments, using Array.prototype.slice(0, n).
  • Omit the second argument, n, to uncurry up to depth 1.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const uncurry = (fn, n = 1) => (...args) => {
  const next = acc => args => args.reduce((x, y) => x(y), acc);
  if (n > args.length) throw new RangeError('Arguments too few!');
  return next(fn)(args.slice(0, n));
};
const add = x => y => z => x + y + z;
const uncurriedAdd = uncurry(add, 3);
console.log(uncurriedAdd(1, 2, 3));

Sample Output:

6

Pictorial Presentation:

JavaScript Fundamental: Uncurry a function up to depth n.

Flowchart:

flowchart: uncurry a function up to depth n

Live Demo:

See the Pen javascript-basic-exercise-114-1 by w3resource (@w3resource) on CodePen.


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JavaScript: Tips of the Day

Chunks an array into n smaller arrays

Example:

const tips_chunkIntoN = (arr, n) => {
  const size = Math.ceil(arr.length / n);
  return Array.from({ length: n }, (v, i) =>
    arr.slice(i * size, i * size + size)
  );
}
console.log(tips_chunkIntoN([1, 2, 3, 4, 5, 6, 7,8], 4));

Output:

[[1,2],[3,4],[5,6],[7,8]]