Check in an array in java if value is lower than previous value and split it

Question

I have an array with times

String[] times = {"08:00", "09:15", "09:45", "08:15", "08:45", "09:30"};

And I want to loop through every value of the array and check if it is higher than the previous value. If that is true, it splits the array at that point so you get these two arrays:

String[] times1 = {"08:00", "09:15", "09:45"};
String[] times2 = {"08:15", "08:45", "09:30"};

How to do this in java?

possible duplicate of [Time comparison](http://stackoverflow.com/questions/2309558/time-comparison) — ThreeFx, Aug 09 '14 at 12:25
I get stuck at checking if the value is lower, becouse it's a time. and the biggest problem is (when the value is lower) to split it there. — user3568362, Aug 09 '14 at 12:25

Dici · Answer 1 · 2014-08-09T12:36:55.427

To split the array, simply use Arrays.copyOfRange to copy the left part and the right part in two new arrays.

//You first determine the split index
int splitIndex  = 2;
String[] times  = {"08:00", "09:15", "09:45", "08:15", "08:45", "09:30"};
String[] times1 = Arrays.copyOfRange(times,0,splitIndex + 1);
String[] times2 = Arrays.copyOfRange(times,splitIndex + 1,times.length);

To compare the time values, you can parse those simple strings by yourself.

public static int compareDates(String d1, String d2) {
        String[] split1 = d1.split(":");
        String[] split2 = d2.split(":");

        int n1 = Integer.parseInt(split1[0]);
        int n2 = Integer.parseInt(split2[0]);

        if (n1 != n2)
            return Integer.compare(n1,n2);
        return Integer.compare(Integer.parseInt(split1[1]),Integer.parseInt(split2[1]));
    }

The rest is up to you, you just need to iterate over the main array and use those two pieces of code in your loop.

score 0 · Accepted Answer · answered Aug 09 '14 at 12:42

0

Use following code:

String[] times = {"08:00", "09:15", "09:45", "08:15", "08:45", "09:30"};
    String first[]=null;
    String second[]=null;
    for(int i=0;i<times.length-1;i++)
    {
        Date date=new SimpleDateFormat("hh:mm").parse(times[i]);
        Date date2=new SimpleDateFormat("hh:mm").parse(times[i+1]);
        if(date.getTime()>date2.getTime())
        {
            first=Arrays.copyOfRange(times, 0, i+1);
            second=Arrays.copyOfRange(times, (i+1), (times.length));
        }
    }

Hope it helps.

answered Aug 09 '14 at 12:42

Darshan Lila

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Why are you creating two new SimpleDateFormats per iteration? – Keppil Aug 09 '14 at 19:44
And why are you not reusing the same instance? – Keppil Aug 10 '14 at 11:39
We can use the same instance. But I choose to do this way. – Darshan Lila Aug 11 '14 at 05:12
That is a terrible choice. – Keppil Aug 11 '14 at 06:36
What are you expecting? – Darshan Lila Aug 11 '14 at 06:46

Check in an array in java if value is lower than previous value and split it

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