practice-test-answer.md

Practice test answer

Prompt:

Write a script, where you:

• Store the following Array: [0,1,2,3,4,5]
• Create a function that increments each number in the array by one
• Call this function ten times

Sample solution

Note:

• There are many ways to write code that does the same thing.

  • What you name your functions doesn't matter that much, if your function wasn't called incrementArray, don't worry in the slightest

  • A "right" answer would follow roughly the same logic, even if the code doesn't look exactly the same.

• Instead of comparing directly to the answer, check out the possible mistakes, and make sure you can understand why code that looked like those answers wouldn't be considered "good"

// Store the Array
let arr = [0, 1, 2, 3, 4, 5];

// Create a function that we can re-use somewhere else in the code
function incrementArray() {
  // Use a for loop to run a bit of code on every item of the array
  for (let index = 0; index < arr.length; index++) {
    // increment every item of the array
    arr[index] += 1;
  }
}

// Use another for loop to call the function ten times
for (let x = 0; x < 10; x++) {
  incrementArray();
}

Possible mistakes

These don't necessarily mean the code would fail to execute, but that the problem wasn't approached correctly

Not using a for loop on incrementArray

As you can see, this becomes hard to read and maintain (if we change the size of the array, we'd need to change our function too)

function incrementArray() {
  arr[0] += 1;
  arr[1] += 1;
  arr[2] += 1;
  arr[3] += 1;
  arr[4] += 1;
  arr[5] += 1;
}

Calling incrementArray ten times by typing it out

This also becomes hard to read and modify, using a loop makes it easier to modify later on, because if you want to call the function more/less times, you only need to change one value instead of modifying multiple lines of code

incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();
incrementArray();