Closing Time explainer

Puzzle Explainer
#1

The aim of this puzzle: Change every other value in the array to '8pm'.

Walkthrough of the solution: The closingTimes array is imported from 'grasshopper.store'. It starts out with each element as '5pm'. The For Loop goes through each item as sets the value to '5pm', but that doesn’t really change anything because it’s the same value. Change the '5pm' to '8pm'.

Now if you run the code, all the values are changed to '8pm', but we were only supposed to make every other value '8pm'. Notice that the i variable determines which array index to use. We want to change the elements at index 0, 2, 4, and 6. That means, we want to increase i by 2 each loop instead of 1. Change i += 1 in the For Loop setup into i += 2.

Sample code solution:
(Tap below to reveal)

import { closingTimes } from 'grasshopper.store';
console.log(closingTimes);
for (let i = 0; i < closingTimes.length; i += 2) {
  closingTimes[i] = '8pm';
}
console.log(closingTimes);

JavaScript Concepts: Array Indexing, Assignment Operator (+=), Code Block (for loop), import, .length()
Additional Code (hidden code that runs before the puzzle’s code):

let closingTimes = ['5pm', '5pm', '5pm', '5pm', '5pm', '5pm', '5pm'];
1 Like
#3

We should all return here, and double check …:joy:

3 Likes
#4

Hello, I don’t know if I told the device to log 9pm to the console every other time or if I actually changed the information contained in the “hidden array”! Can you clarify, please?

#5

Hey there, you’ve done both!

The array looks like this when it is imported into the puzzle:

let closingTimes = ['5pm', '5pm', '5pm', '5pm', '5pm', '5pm', '5pm'];

Then, the for loop is changing the value of every other item in the array:

for (let i = 0; i < closingTimes.length; i += 2) {
    closingTimes[i] = '8pm';
}

The array now looks like this:

['8pm', '5pm', '8pm', '5pm', '8pm', '5pm', '8pm']

Then finally, you’re printing the entire array:

console.log(closingTimes);

Hope that clears things up. Let me know if you have any questions.
Ben

1 Like
#7

But why you need i += 2, instead of i += 1?? Why do you need to keep indexes 1,3,5 at 5pm and change the others to 9 pm?

#8

You need i += 2 since the question stated to chance every other time. i += 1 would make you access every single time, whereas i += 2 accesses only every other element