ArrayList search
In this chapter you will learn:
Get object for index
int indexOf(Object o)
Returns the index of the first occurrence, or -1 if this list does not contain the element.
int lastIndexOf(Object o)
Returns the index of the last occurrence, or -1 if this list does not contain the element.
import java.util.ArrayList;
//from j a v a 2 s . c om
public class Main {
public static void main(String args[]) {
ArrayList<String> al = new ArrayList<String>();
al.add("C");
al.add("java2s.com");
al.add("D");
al.add("F");
al.add(1, "java2s.com");
System.out.println(al);
System.out.println(al.indexOf("java2s.com"));
System.out.println(al.lastIndexOf("java2s.com"));
}
}
The output:
If contain a certain object
boolean contains(Object o)
Returns true if this list contains the specified element.
import java.util.ArrayList;
import java.util.List;
/*from j a va2 s .c o m*/
public class Main {
public static void main(String args[]) {
ArrayList<String> al = new ArrayList<String>();
al.add("C");
al.add("A");
al.add("E");
al.add("java2s.com");
al.add("D");
al.add("F");
al.add(1, "java2s.com");
System.out.println(al);
System.out.println(al.contains("java2s.com"));
}
}
The output:
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What you will learn in the next chapter:
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