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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Build a Quiz Challenge, Part 2 Solution

H Yang
H Yang
2,066 Points
Posted by H Yang
H Yang
2,066 Points

Building a list

One mistake I made with this problem was that even though I made one-dimensional arrays to contain my correct and incorrect answers, I tried to call the data point from the array using a two-dimensional name- arr[i][0].

function printList (list) {
  var listHTML = "<ol>";
  for ( var i=0; i < list.length; i += 1) {
    listHTML += "<li>" + list[i][0] + "</li>";
  }
  listHTML += "</ol>";
  print(listHTML);
}

When I did this my buildList function spit out a list that looked like this:

1) H 2) H 3) H

The printList function worked normally when I called the information using list[i] instead of list[i][0].

What's going on with the function making a list of H's? And is it possible to call information out from two-dimensional arrays?

1 Answer

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Henry,

If your list is one-dimensional then it looks like each element in that array begins with an 'H'. Is that the case?

If it's an array of strings, then doing something like list[0][0] is going to give you the first character of the first string.

The first [0] will access the first string of the array. The second [0] will access the first character of that string.

console example:

> var list = ["hello", "goodbye"]
  undefined
> list
  ["hello", "goodbye"]
> list[0]
  "hello"
> list[0][0]
  "h"

Yes, it's possible to get individual elements from 2 dimensional arrays.

The first index gets you one of the inner arrays and the second index gets you an element from that inner array.

H Yang
H Yang
2,066 Points
H Yang
H Yang
2,066 Points

Wow you're completely correct- the first word of each string was "How", hence the list of "H's". Thank you again Jason.