通过for循环获取最小值及其索引

Question

How can I get the minimum value in a for loop plus its index:?

Update: This is what I tried after using @Sakalya 's answer

      LatLng myLatLang = new LatLng(myLocation.getLatitude(),myLocation.getLongitude());

        double minval = -1.0;
        int minIndex = 0;

        for (int i = 0; i < stationsCoord.size(); i++) {

            double distance = CalculationByDistance(myLatLang,stationsCoord.get(i));

            if(distance < minval){
                minval = distance;
                minIndex = i;
            }

            Log.i("distance " , String.valueOf(distance));

            System.out.println("min=" +minval+ "index="+minIndex);

        }

      //i'm looking for the min value of 'distance' + the index 'i'

I always get this: System.out: min=-1.0index=0

Thank you in advance.

Answer 1

First you can set a min variable to 1000000 and then iterate the list to find min value as below:

LatLng myLatLang = new LatLng(myLocation.getLatitude(), myLocation.getLongitude());

double minval = 1000000000000.0;
int minIndex = 0;

for (int i = 0; i < stationsCoord.size(); i++) {

    double distance = CalculationByDistance(myLatLang,stationsCoord.get(i));

    if (distance < minval) {
      minval = distance;
      minIndex = i;
    }

    Log.i("distance " , String.valueOf(distance));

    System.out.println("min=" +minval+ "index="+minIndex);

}

Answer 2

In the following code

double minval = -1.0;
if (somepositivedistance < minval ) { // do something
}

nothing will ever return true if the distance is positive, therefore the statement will never execute.

You need to set minval to something greater then the largest possible distance (for example Double.MAX_VALUE ) before entering the for-loop.