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Using for-each loop, we can iterate over the elements of any collection class that implements Iterable interface and because all the collection classes implements Iterable interface, so we can cycle through their elements using for-each loop in a very easy manner, let's see how.

Using for-each loop to iterate over a collection with String objects.

In this example we are iterating elements of ArrayList that is holding String objects using for-each loop.

import java.util.*;

class ForEachEx
{
public static void main(String... ar)
{
ArrayList<String> arr= new ArrayList<String>();

arr.add("C");
arr.add("A");
arr.add("4");
arr.add("F");
arr.add("X");
arr.add("1");



System.out.print("Iterating contents of collection using For-each : ");

for(String s : arr)		//for-each loop
{	
	System.out.print(s + " " );
}

System.out.println("\nSize of arraylist : " + arr.size());
}

}

Output is - :

Initial size of arraylist = 0
Iterating contents of collection using For-each : C A 4 F X 1
Size of arraylist : 6

• In this code above, we have added a few String objects to ArrayList<String> and then we have used for-each loop to iterate over its elements.

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Using for-each loop to iterate over a collection with Integer objects.

In this example we are iterating elements of ArrayList that is holding String objects using for-each loop.

import java.util.*;

class ForEachEx
{
public static void main(String... ar)
{
ArrayList<Integer> arr= new ArrayList<Integer>();

System.out.printl("Initial size of arraylist"+ arr.size());

arr.add(10);
arr.add(30);
arr.add(5);
arr.add(40);
arr.add(15);
arr.add(50);


System.out.print("Iterating over a collection class using for-each");
System.out.print("Elements in this collection class : ");
for(int i : arr)		//for-each loop
{	
	System.out.print(i + " " );
}

System.out.println("\nSize of arraylist : " + arr.size());
}

}

Output is - :

Initial size of arraylist = 0
Iterating over a collection using for-each
Elements in this collection class : 10 30 5 40 15 50
Size of arraylist : 6

• In this code above, we have added a few String objects to ArrayList<Integer> and then we have used for-each loop to iterate over its elements.

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