What does double brackets mean in this condition?

Question

This below is my for-loop and im a beginner so i need help to understand what [i] means where it says ".checked" and ".value". Also, does "var i" stand for "variable i"? Side note: this loop is for a list of checkboxes.

for (var i=0; i<flightprices.length; i++) {

if (flightprices.length[i].checked) {

flightPrice = +flightprices[i].value;
}}

that code `flightprices.length[i]` is just wrong. It should be `flightprices[i].checked` — epascarello, Dec 08 '17 at 01:52
Yes my code does execute, i just need to understand what im doing — Sjan, Dec 08 '17 at 02:05
Tutorials.. I would appreciate if i just could get some answes to my questions haha — Sjan, Dec 08 '17 at 02:07

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

1

Ignoring the fact that this code results in an error, I can tell you the following.

var i=0; is defining a variable named i to the value 0.
flightprices[i] means the i+1th element of the array flightprices. [] notation is an array selector. Because JavaScript is 0-indexed, flightprices[0] means the first element, flightprices[1] is the second element, and so on.

Why there is an error

This line:

if (flightprices.length[i].checked) {

tries to find element i of flightprices.length, however the length of something is always an integer, and integers aren't arrays.

edited Jun 20 '20 at 09:12

Community

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answered Dec 08 '17 at 02:07

ericw31415

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So in this case, "[i]" or "i+1th" basically means the checked element that the variable "i" selected in the loop? – Sjan Dec 08 '17 at 02:24
@Sjan Correct, the `if` is checking every value in `flightprices` to see if they are checked or not. – ericw31415 Dec 08 '17 at 02:28
Thank you so much! – Sjan Dec 08 '17 at 02:37

What does double brackets mean in this condition?

1 Answers1

Why there is an error