Hello everyone I have a class named GEN and I have an array of this what I want to to is sort this array based on time variable So theone with the shortest time must be the gend[0]. I hope I explained my question clear and I am using NetBeans
public class GEN
{
int[][] mark=new int[TIMELIMIT][N+1];
int[][] dimark=new int[TIMELIMIT][N+1];
int time=0;
int[] touched=new int[N+1];
}
public GEN[] gend=new GEN[GENNUM];
You need to implement Comparable.
public class GEN implements Comparable<GEN>
{
int[][] mark=new int[TIMELIMIT][N+1];
int[][] dimark=new int[TIMELIMIT][N+1];
int time=0;
int[] touched=new int[N+1];
int compareTo(GEN obj)
{
// compareTo returns a negative number if this is less than obj,
// a positive number if this is greater than obj,
// and 0 if they are equal.
return this.time - obj.time;
}
}
public GEN[] gend=new GEN[GENNUM];
By implementing Comparable, you are then able to use Arrays.sort() to sort your array once it is populated with GEN objects. The sort function uses compareTo to determine the proper ordering of the objects. Thus, once you've implemented Comparable, you only need to write:
Arrays.sort(gend);
Seriously, you should check out the Java docs link Luke Willis posted in his answer, its pretty impressive to see the sheer number of classes (a good chunk of which are used very frequently) which are "Known implementing classes". If you go over that list and consider how powerful compare can be for the classes you are familiar with (if you are familiar with auto-boxing/unboxing then you will be, if not, you can click on those classes at that spot in the Java doc.
You can sit there and try to figure out for the first time how to code an algorithm that sorts for example an ArrayList<SomeObjectType> arrList based on an instance variable of each object inside, such as Card objects' primitive int faceValue...
...60+ minutes later since you are unfamiliar with how to create a sorting algorithm it will take a while. Also, it will be a hefty chunk of somewhat obfuscated code.
...or you could just read up on Comparable and implement it.
Edit: Not to say that making an algorithm by hand would be a bad thing, it would definitely be a good learning experience, but Comparable is such a powerful and condense tool to implement in your code.