Hello i have some simple code like this
String[] myString1= {"Hidayat", "20"};
outerArr.add(myString1);
String[] myString2= {"Ryan", "10"};
outerArr.add(myString2);
String[] myString2= {"irwan", "5"};
outerArr.add(myString2);
anyone know how to sort array outerArr with ascending by number?
You can use Comparator interface for custom sorting:
Collections.sort(outerArr, new Comparator<String[]>() {
public int compare(String[] o1, String[] o2)
{
// for example you can compare integers
return Integer.parseInt(o2[1]) - Integer.parseInt(o1[1]);
}
});
For that case i prefer TreeMap.The TreeMap class implements the Map interface by using a tree. A TreeMap provides an efficient means of storing key/value pairs in sorted order, and allows rapid retrieval.
TreeMap<String, String> map = new TreeMap<>();
map.put("20", "Hidayat");
map.put("10", "Ryan");
map.put("5", "irwan");
For retrieving the values
map.get("10"); // output = Ryan
Another way to do this if you are using Java 8 is using Lambda, first create a class contain 2 member fields for the string and the number with getter for each member and then called this way :
outerArr.sort((Person o1, Person o2)->o1.getAge()-o2.getAge());
If you don't want to create a new class you can call :
outerArr.sort((String[] o1, String[] o2)->Integer.parseInt(o1[1])-Integer.parseInt(o2[1]));
