CODEWITHSUNDEEP
javascript
trainee
trainee

Reputation: 47

overload the overloadedFunc() function

I need to overload a function overloadedFunc() which takes 3 arguments. For the 1st argument of the function set the default value [1, 2, 3], for the 2nd - the value 2, for the 3rd - the function that returns the product of the first two arguments, and the function can multiply both arrays and numbers. The overloadedFunc() function returns the result of the default function. I have a code but it throws an error. How can I solve this problem?

function overloadedFunc(arg1 = [1, 2, 3], arg2 = 2, arg3 = multiply()) {
  const res = multiply(arg1, arg2);
  return res;
}

function multiply(arg1, arg2) {
  arg1.forEach((item) => {
    item * arg2;
  });
}

console.log(overloadedFunc()); // [2, 4, 6]
console.log(overloadedFunc([2, 4, 6], 3)); // [6, 12, 18]
console.log(overloadedFunc(10)); // 20

Upvotes: 0

Views: 49

Answers (2)

Mr. Polywhirl
Mr. Polywhirl

Reputation: 48600

In overloadedFunc, you need to take multiply as a default (do not invoke the function); and you need to call arg3.

You can simplify the multiply function to return a mapping.

const multiply = (arr, n) =>
  Array.isArray(arr)
    ? arr.map(x => x * n)
    : arr * n;

const overloadedFunc = (
  arg1 = [1, 2, 3],
  arg2 = 2,
  arg3 = multiply
) =>
  arg3(arg1, arg2);


console.log(overloadedFunc());             // [2, 4, 6]
console.log(overloadedFunc([2, 4, 6], 3)); // [6, 12, 18]
console.log(overloadedFunc(10));           // 20
.as-console-wrapper { top: 0; max-height: 100% !important; }

This can be re-written to simplify the arg3 (aka multiply) callback.

const multiply = (scalar, multiplier) => scalar * multiplier;

const overloadedFunc = (
  arg1 = [1, 2, 3],
  arg2 = 2,
  arg3 = multiply
) =>
  Array.isArray(arg1)
    ? arg1.map(x => arg3(x, arg2))
    : arg3(arg1, arg2);


console.log(overloadedFunc());             // [2, 4, 6]
console.log(overloadedFunc([2, 4, 6], 3)); // [6, 12, 18]
console.log(overloadedFunc(10));           // 20
.as-console-wrapper { top: 0; max-height: 100% !important; }

Upvotes: 1

Mustafa Reda
Mustafa Reda

Reputation: 376

look at the 3rd parameter, you are calling the function multiply() without any parameters, if you wanna send the reference use multiply

The code will be like this:

// fixing the 3rd parameter 
function overloadedFunc(arg1 = [1, 2, 3], arg2 = 2, arg3 = multiply) {
    const res = multiply(arg1, arg2);
    return res;
}

// return the result in multiply function 
function multiply(arg1, arg2) {
  arg1.forEach((item) => {
    item * arg2;
  });   
  return arg1;
}

// fix the 3rd call to use [10] in array instead of 10 as a number
console.log(overloadedFunc()); // [2, 4, 6]
console.log(overloadedFunc([2, 4, 6], 3)); // [6, 12, 18]
console.log(overloadedFunc([10])); // [20]

Upvotes: 0

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