For each loop in java 8 javatpoint example

For each loop in java 8 javatpoint example

I'd be happy to explain the concept of loops in Java 8 using Javatpoint examples.

For Loop

The for loop is used when you need to execute a block of code repeatedly based on the value of a counter variable. In Java, you can use the enhanced for loop (also known as the "for-each" loop) or the traditional for loop.

Here's an example using Javatpoint:

// Traditional For Loop Example
int[] numbers = {1, 2, 3, 4, 5};
for (int i = 0; i < numbers.length; i++) {
System.out.println("Number: " + numbers[i]);
}
// Enhanced For Loop Example
int[] numbers = {1, 2, 3, 4, 5};
for (int number : numbers) {
System.out.println("Number: " + number);
}

In the traditional for loop example, we declare a variable i and initialize it to 0. We then use this variable in the loop condition to check if we have reached the end of the array. In each iteration, we print out the value at the current index.

In the enhanced for loop example, we don't need to declare or initialize a counter variable. Instead, we use the for keyword followed by a colon and the type of the elements in the array. The compiler then generates the necessary code to iterate over the array using the counter variable.

While Loop

The while loop is used when you want to execute a block of code repeatedly as long as a certain condition is true.

Here's an example using Javatpoint:

int i = 0;
while (i < 5) {
System.out.println("Number: " + i);
i++;
}

In this example, we initialize the variable i to 0 and then use a while loop to print out numbers from 0 to 4. The condition in the while loop is checked at the beginning of each iteration, and if it's true, the code inside the loop body is executed.

Do-While Loop

The do-while loop is similar to the while loop, but it checks the condition after executing the loop body once.

Here's an example using Javatpoint:

int i = 0;
do {
System.out.println("Number: " + i);
i++;
} while (i < 5);

In this example, we print out numbers from 0 to 4 using a do-while loop. The condition is checked after the code inside the loop body has been executed once.

Foreach Loop

The foreach loop (also known as the "for-each" loop) is used when you want to iterate over an array or collection and perform some operation on each element.

Here's an example using Javatpoint:

List names = Arrays.asList("John", "Emma", "Robert");
for (String name : names) {
System.out.println(name);
}

In this example, we use a foreach loop to iterate over the list of names. We don't need to declare or initialize an index variable; instead, we use the name variable in each iteration.

These are some basic examples of loops in Java 8 using Javatpoint. I hope this helps!

foreach() in java 8 stream

I'm happy to help you with that! However, please note that I'll be responding in English only.

forEach() in Java 8 Stream

In Java 8, the forEach() method was introduced as a part of the Stream API. It's a powerful tool for processing streams of data, allowing you to perform operations on each element in the stream without having to explicitly iterate over the elements using a traditional loop.

The forEach() method is used to apply an action (an operation) to each element in a stream. The method takes a Consumer as its argument, which defines the action to be performed on each element. A Consumer is an interface that has a single abstract method, accept(), which takes one argument and returns void.

Here's the general syntax of the forEach() method:

stream.forEach(action);

In the above code snippet:

Example Usage

Let's consider an example where we have a list of integers and we want to print each integer in the list:

List numbers = Arrays.asList(1, 2, 3, 4, 5);
numbers.stream()
.forEach(System.out::println);

In this example:

When you run this code, it will print each integer in the list:

1
2
3
4
5

Benefits

The forEach() method has several benefits:

Common Pitfalls

When using forEach(), it's essential to avoid common pitfalls:

In conclusion, forEach() in Java 8 Stream is a powerful tool for processing streams of data. By understanding its benefits and avoiding common pitfalls, you can write more concise, expressive, and maintainable code.