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How to get the first element of the List in Java?
The List interface extends Collection interface. It is a collection that stores a sequence of elements. ArrayList is the most popular implementation of the List interface. User of a list has quite precise control over where an element to be inserted in the List. These elements are accessible by their index and are searchable.
List interface provides a get() method to get the element at particular index. You can specify index as 0 to get the first element of the List. In this article, we're exploring get() method usage via multiple examples.
Syntax
E get(int index)
Returns the element at the specified position.
Parameters
index - index of the element to return.
Returns
The element at the specified position.
Throws
IndexOutOfBoundsException - If the index is out of range (index < 0 || index >= size())
Example 1
Following is the example showing how to get the first element from a List.
package com.tutorialspoint;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class CollectionsDemo {
public static void main(String[] args) {
List<Integer> list = new ArrayList<>(Arrays.asList(4,5,6));
System.out.println("List: " + list);
// First element of the List
System.out.println("First element of the List: " + list.get(0));
}
}Output
This will produce the following result −
List: [4, 5, 6] First element of the List: 4
Example 2
Following is the example where getting the first element from a List can throw an exception.
package com.tutorialspoint;
import java.util.ArrayList;
import java.util.List;
public class CollectionsDemo {
public static void main(String[] args) {
List<Integer> list = new ArrayList<>();
System.out.println("List: " + list);
try {
// First element of the List
System.out.println("First element of the List: " + list.get(0));
} catch(Exception e) {
e.printStackTrace();
}
}
}Output
This will produce the following result −
List: [] java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 at java.util.ArrayList.rangeCheck(ArrayList.java:659) at java.util.ArrayList.get(ArrayList.java:435) at com.tutorialspoint.CollectionsDemo.main(CollectionsDemo.java:11)
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