There are 10,000 possible combinations for 4-digit pin number using digits 0-9. In this program, we'll see how we can use loops to guess that a 4-digit pin in only a few seconds.

Create a global variable called pinCode and set it to a 4-digit code using 0-9. Since we want the pin code to support combinations starting with 0, we'll want to use a string instead of a number:

var pinCode = "0049";

Create a function called check that takes a possible combination in as a parameter and returns either true or false.

Write a loop (for or while) that iterates through every number from 0 - 9999, checking each one for the combination. The loop should terminate if it guesses correctly or if it reaches 9999.

Use the provided leftPad function to turn your numbers in to 4-digit pins with leading 00's. For example:

var a = 10;
var as = leftPad(10, 4);
// as is now "0010"

Submit the assignment by submitting a pull request. The steps to do that are as follows:

1. To start, fork the repository.
2. Clone the repository to your computer.
3. Modify the files and commit changes to complete your solution.
4. Push/sync the changes up to GitHub.
5. Create a pull request on the original repository to turn in the assignment.