Java for-each Loop

In this tutorial, we will learn about the Java for-each loop and its difference with for loop with the help of examples.

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

Input

// 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

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

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

Example 2: Sum of Array Elements

Input

// 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:

Iteration	Variables
1	`number` = 3 `sum` = 0 + 3 = 3
2	`number` = 4 `sum` = 3 + 4 = 7
3	`number` = 5 `sum` = 7 + 5 = 12
4	`number` = -5 `sum` = 12 + (-5) = 7
5	`number` = 0 `sum` = 7 + 0 = 7
6	`number` = 12 `sum` = 7 + 12 = 19

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

Input

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

Input

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.

Java for-each Loop

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