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sumitanantwar
1,511 PointsError in for loop ?
Here we are trying to loop from the tapped index to the last index of the MutableList, simultaneously removing the elements from the List... So, for example...
var integers: MutableList<Int> = arrayListOf(0,1,2,3,4,5,6,7,8,9)
for (i in 5..integers.lastIndex)
{
integers.removeAt(i)
System.out.println(integers.toString())
}
LOOP 1-------------------
i = 5
integers = [0,1,2,3,4,6,7,8,9] // "5" at Index 5 removed
LOOP 2-------------------
i = 6
integers = [0,1,2,3,4,6,8,9] // "7" at Index 6 removed
LOOP 3-------------------
i = 7
integers = [0,1,2,3,4,6,8] // "9" at Index 7 removed
LOOP 4-------------------
i = 8
integers = [0,1,2,3,4,6,8] // Index 8 OUT OF BOUNDS
We should rather loop backwards
for (i in integers.lastIndex downTo 5)
{
integers.removeAt(i)
System.out.println(integers.toString())
}
Console -------------------
[0, 1, 2, 3, 4, 5, 6, 7, 8]
[0, 1, 2, 3, 4, 5, 6, 7]
[0, 1, 2, 3, 4, 5, 6]
[0, 1, 2, 3, 4, 5]
[0, 1, 2, 3, 4]
-----------------------------
2 Answers
Ben Deitch
Treehouse TeacherYep, that's correct! In the next two videos we add tests for adding/removing cards and we find/fix that bug :)
sumitanantwar
1,511 PointsYes! :) Just now watched those videos! I should had wondered. It would had been really weird to have missed such a blunder. Sorry for my impatience!
Anyways, the course content is great! Thanks for the efforts.