Java Iterator and Iterable practical analysis: cleverly handle various data structures

php editor Strawberry brings you a wonderful article: "Practical Analysis of Java Iterator and Iterable: Cleverly Handling Various Data Structures". This article will delve into the use of Iterator and Iterable interfaces in Java to help readers better handle various data structures and improve code efficiency and readability. Let’s learn these practical skills together and improve your Java programming skills!

Array is one of the simplest data structures. It can store a series of elements, and the types of the elements must be the same. To iterate over an array, you can use the following code:

int[] numbers = {1, 2, 3, 4, 5};
for (int number : numbers) {
System.out.println(number);
}

This code will output all elements in the array.

2. List

List is another commonly used data structure, which is similar to an array but more flexible. Lists can store different types of data and can be resized dynamically. To iterate over a list you can use the following code:

List<String> names = new ArrayList<>();
names.add("John");
names.add("Mary");
names.add("Bob");

for (String name : names) {
System.out.println(name);
}

This code will output all elements in the list.

3. Collection

Set is another important data structure that can store a set of unique elements. To iterate over a collection, you can use the following code:

Set<Integer> numbers = new HashSet<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);

for (int number : numbers) {
System.out.println(number);
}

This code will output all elements in the collection.

4. Mapping

A map is a data structure that maps keys to values. To iterate over the map, you can use the following code:

Map<String, Integer> ages = new HashMap<>();
ages.put("John", 25);
ages.put("Mary", 30);
ages.put("Bob", 35);

for (Map.Entry<String, Integer> entry : ages.entrySet()) {
System.out.println(entry.geTKEy() + " = " + entry.getValue());
}

This code will output all key-value pairs in the map.

5. Custom data structure

You can also use Iterator and Iterable to iterate over custom data structures. For example, you can create your own LinkedList class and implement the Iterator interface. This way you can use the above code to iterate over all elements in the linked list.

in conclusion

Java Iterator and Iterable are two powerful tools that can help you iterate over various data structures easily. By understanding how to use them, you can process data more easily and write more robust code.

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