Function Currying in JavaScript Recursively

What is function currying?

Function currying is a process in functional programming in which a function with multiple arguments can be transformed into a sequence of nesting functions.

Example of function currying:

The following is the code example of function currying:

const mul = (x) => {
   return (y) => x * y;
}

console.log(mul(2)(3));

Most common and tricky interview question about function curry

The problem solution:

const mul = (x) => {
    return (y) => {
        if (y) {
            return mul(x * y);
        } else {
            return x;
        }
    }
};

console.log(mul(5)(3)(2)(4)()) // 120