JavaScript: Optional function parameters

In programming, many functions and methods have parameters that rarely change. In such cases, these parameters are given default values that can be changed as needed. This reduces the number of duplicates in your code. An example:

// Exponentiation function.
// The second parameter is 2 by default
const pow = (x, base = 2) => {
  return x ** base;
};
// 3 to the second power (two is set by default)
pow(3); // 9
// three to the third power
pow(3, 3); // 27

The default value looks like a normal assignment within the definition. It only works if the parameter is not passed. This is something you should get used to. There can even be a default value when there is only one parameter:

const print = (text = 'nothing') => console.log(text);

print(); // "nothing"
print("Hexlet"); // "Hexlet"

There can be any number of default parameters:

const f = (a = 5, b = 10, c = 100) => { ... }

The default values have one limitation. They should be at the very end of the parameter list. From the point of view of syntax, it's impossible to create a function that will have a mandatory parameter after an optional one:

// Such code will terminate with an error
const f = (a = 5, b = 10, c = 100, x) => { ... }
// As well as this one
const f = (a = 5, x, b = 10, c = 100) => { ... }

// But this one will work
const f = (x, a = 5, b = 10, c = 100) => { ... }

// This one will work too
const f = (x, y, a = 5, b = 10, c = 100) => { ... }

Instructions

Write the getHiddenCard() function that takes a credit card number (consisting of 16 digits) as a string and returns its hidden version, which can be used on the website to display. If the original card had the number 2034399002125581, the hidden version will look like ****5581. In other words, the function replaces the first 12 digits with asterisks. The number of asterisks is specified by a second optional parameter. Its default value is 4

// The credit card number is passed as a string
getHiddenCard("1234567812345678", 2); // "**5678"
getHiddenCard("1234567812345678", 3); // "***5678"
getHiddenCard('1234567812345678');    // "****5678"
getHiddenCard('2034399002121100', 1); // "*1100"

To complete the task, you'll need the repeat() string method, which repeats a string a given number of times.

"+".repeat(5); // "+++++"
"o".repeat(3); // "ooo"