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 Sytnax
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
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
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
Output:
a e i o u
2. Using for-each Loop
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.