Java for-each Loop

In Java, the for-each loop is used to iterate through elements of arrays and collections (like ArrayList). It is also known as the enhanced for loop.

for-each Loop Syntax

The syntax of the Java for-each loop is:

for(dataType item : array) {
    ...
}

Here,

• array - an array or a collection
• item - each item of array/collection is assigned to this variable
• dataType - the data type of the array/collection

Example 1: Print Array Elements

// print array elements 

class Main {
  public static void main(String[] args) {
      
    // create an array
    int[] numbers = {3, 9, 5, -5};
    
    // for each loop 
    for (int number: numbers) {
      System.out.println(number);
    }
  }
}

Output

3
9
5
-5

Here, we have used the for-each loop to print each element of the numbers array one by one.

• In the first iteration, item will be 3.
• In the second iteration, item will be 9.
• In the third iteration, item will be 5.
• In the fourth iteration, item will be -5.

Example 2: Sum of Array Elements

// Calculate the sum of all elements of an array

class Main {
 public static void main(String[] args) {
  
   // an array of numbers
   int[] numbers = {3, 4, 5, -5, 0, 12};
   int sum = 0;

   // iterating through each element of the array 
   for (int number: numbers) {
     sum += number;
   }
  
   System.out.println("Sum = " + sum);
 }
}

Output:

Sum = 19

In the above program, the execution of the for each loop looks as:

As we can see, we have added each element of the numbers array to the sum variable in each iteration of the loop.

for loop Vs for-each loop

Let's see how a for-each loop is different from a regular Java for loop.

1. Using for loop

class Main {
 public static void main(String[] args) {
    
   char[] vowels = {'a', 'e', 'i', 'o', 'u'};

   // iterating through an array using a for loop
   for (int i = 0; i < vowels.length; ++ i) {
     System.out.println(vowels[i]);
   }
 }
}

Output:

a
e
i
o
u

2. Using for-each Loop

class Main {
 public static void main(String[] args) {

   char[] vowels = {'a', 'e', 'i', 'o', 'u'};
  
   // iterating through an array using the for-each loop
   for (char item: vowels) {
     System.out.println(item);
   }
 }
}

Output:

a
e
i
o
u

Here, the output of both programs is the same. However, the for-each loop is easier to write and understand.

This is why the for-each loop is preferred over the for loop when working with arrays and collections.