Community

Question

I've got an array with multiple numbers in it, and i want to take every 15th value in this array and copy it into a different array.

is that possible(preferably without a loop)?

Answer 1

0

It's certainly possible, but I don't know how I would do it without a loop, I'm afraid. A loop is the most elegant way traverse arrays.

I would do something like this:

public string[] TakeEvery15th(string[] source)
{
    string[] every15th = new string[source.Length / 15];

    for (int i = 15, j = 0; i < source.Length; i += 15, j++)
    {
        every15th[j] = source[i];
    }

    return every15th;
}

Notice in particular the double counters inside the for-loop. The variable i causes the counter to jump 15 steps at a time in the source array, while the variable j sticks those values in 0, 1, 2... in the destination array.

answered Jul 21 '11 at 09:28 AM

CHPedersen
6k ● 13 ● 22 ● 61

looking good and logic, could've slapped myself for not doing that.

also, are you sure this is javascript?

Jul 21 '11 at 09:41 AM biohazard

I have replaced int[] with string[] to reflect the fact that your numbers are in string format. If you need the strings converted to a number before you return, you can use a parse method, i.e. int.Parse(string) or double.Parse(string), or whatever datatype those numbers are.

This is C#. A translation to javascript should be fairly straight-forward. ;)

Jul 21 '11 at 09:42 AM CHPedersen

translation is going bad, he won't accept the multiple counters in the loop. all the rest is successfully translated

Jul 21 '11 at 09:46 AM biohazard

I'm not familiar with Unity's javascript syntax, so it might be that unlike C#, it doesn't support multiple counters inside for-loops. :/ In that case, you might have to take j out of the for-loop declaration, and increment it manually, like this:

int j = 0; for (int i = 15; i < source.Length; i += 15) { every15th[j] = source[i]; j++; }

Jul 21 '11 at 09:50 AM CHPedersen

loop is starting but doesn't fill the every15th array at all...is there any other solution?

Jul 21 '11 at 09:56 AM biohazard

show 1 more reply

(comments are locked)

Answer 2

0

Something like this should work if you need it in javascript

// assume "source" exists, and is your original array
// "dest" will be your new array.

var dest = [];
var numItems = Math.floor(source.length / 15);

for (var i = 0; i < numItems; ++i) {
    dest.push(source[i * 15]);
}

answered Jul 21 '11 at 11:57 AM

rejj
174 ● 1 ● 1 ● 8

Array modification is quite expensive, and as-per the C#, not necessary since the array size is calculable in advance.

Jul 21 '11 at 12:45 PM Waz

(comments are locked)

Answer 3

0

Spam - Removed by Almo

answered Jul 21 '11 at 12:46 PM

gergerr (suspended)

thanks for the helpful answer? :D :D

Jul 21 '11 at 12:48 PM biohazard

(comments are locked)

Answer 4

0

Spam - Removed by Almo

answered Jul 21 '11 at 12:51 PM

gergerr (suspended)

(comments are locked)

Answer 5

0

[I SHOULD BE SHOT FOR BEING A SPAMBOT]

answered Jul 21 '11 at 12:15 PM

gergerr (suspended)

thanks for the helpful answer? :D :D

Jul 21 '11 at 12:48 PM biohazard

(comments are locked)

Community

Writing certain values of an array into a different array

Follow this question

Welcome to Unity Answers

Unity Answers tutorial video!

Related Questions