Initialize array in Kotlin based on list size

Question

I need to add LineChart(using MpAndroidChart) dynamically in LinearLayout.

I have declared an arrayList,named list.

 val list = arrayListOf<ABC>()
       ....

 for (i in list) {
   chart[] = LineChart(activity)
 }

What is the value I should put inside [] ? Let say the list's saiz is 2, I need to have 2 chart in LinearLayout.

How should I initialize LineChart?

Example

chart[i] = LineChart(activity) ???

LineChart

public class LineChart extends BarLineChartBase<LineData> implements LineDataProvider {

    public LineChart(Context context) {
        super(context);
    }

    public LineChart(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public LineChart(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void init() {
        super.init();

        mRenderer = new LineChartRenderer(this, mAnimator, mViewPortHandler);
    }

    @Override
    public LineData getLineData() {
        return mData;
    }

    @Override
    protected void onDetachedFromWindow() {
        // releases the bitmap in the renderer to avoid oom error
        if (mRenderer != null && mRenderer instanceof LineChartRenderer) {
            ((LineChartRenderer) mRenderer).releaseBitmap();
        }
        super.onDetachedFromWindow();
    }
}

gidds · Accepted Answer · 2019-05-30 11:00:23Z

2

Your question is a little unclear, but I'm following correctly, you can do it in one line like this:

val chart = Array(list.size){ LineChart(list[it]) }

Or:

val chart = list.map{ LineChart(it) }.toTypedArray()

(The latter creates a temporary list, which may be slightly less efficient; but it iterates through the list instead of indexing, which could be faster if the list isn't random-access.)

answered May 30, 2019 at 11:00

gidds

18.9k3 gold badges25 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

AI. Over a year ago

There is an error in line LineChart(it). Error:Type mismatch. Required: Context! Found: ABC

gidds Over a year ago

Perhaps if you posted a minimal, complete, verifiable example (MCVE), we could write some code to fit in with it…?

AI. Over a year ago

I need to have 2 charts. How should I initialize the array?

AI. Over a year ago

any idea for this?

gidds Over a year ago

That's still just code fragments. But I think the rough equivalent would be fun initializePlayers(int playerCount) = Array(playerCount){ Player(it) }. (Note that both Java and Kotlin conventions start functions and variables with a lower-case letter.) That Array constructor takes two params: a size, and a lambda to construct each array element, given its index. So I think that does all you need.

|

AI. · Accepted Answer · 2019-06-01 17:31:24Z

0

This is my answer

for (i in 0 unti list.size) {
   chart[i] = LineChart(activity)
 }

answered Jun 1, 2019 at 17:31

AI.

1,0062 gold badges17 silver badges32 bronze badges

Collectives™ on Stack Overflow

Initialize array in Kotlin based on list size

2 Answers 2

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related