Java Generics - List



Java has provided generic support in List interface.

Syntax

List<T> list = new ArrayList<T>();

Where

  • list − object of List interface.

  • T − The generic type parameter passed during list declaration.

Description

The T is a type parameter passed to the generic interface List and its implemenation class ArrayList.

Example

Create the following java program using any editor of your choice.

package com.tutorialspoint; import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class GenericsTester { public static void main(String[] args) { List<Integer> integerList = new ArrayList<Integer>(); integerList.add(Integer.valueOf(10)); integerList.add(Integer.valueOf(11)); List<String> stringList = new ArrayList<String>(); stringList.add("Hello World"); stringList.add("Hi World"); System.out.printf("Integer Value :%d\n", integerList.get(0)); System.out.printf("String Value :%s\n", stringList.get(0)); for(Integer data: integerList) { System.out.printf("Integer Value :%d\n", data); } Iterator<String> stringIterator = stringList.iterator(); while(stringIterator.hasNext()) { System.out.printf("String Value :%s\n", stringIterator.next()); } } }

This will produce the following result −

Output

Integer Value :10
String Value :Hello World
Integer Value :10
Integer Value :11
String Value :Hello World
String Value :Hi World
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