Overview of application scenarios of different data structures in Java: introduction from arrays to linked lists

Overview of data structures in Java: from arrays to linked lists, to understand the application scenarios of different data structures, you need specific code examples

Abstract:
The data structure is The way data is stored and organized in a computer. For developers, choosing the right data structure can improve the efficiency of algorithms and the readability of code. This article will introduce commonly used data structures in Java, including arrays, linked lists, stacks, queues, and hash tables, and provide application scenarios and corresponding code examples of various data structures.

1. Array (Array)
   Array is the most basic data structure, which can be used to store the same type of data. The characteristic of arrays is that elements can be accessed quickly through indexing, but inserting and deleting elements are less efficient.

// Create an integer array
int[] arr = new int[5];

// Assign a value to the array
arr[0] = 1 ;
arr[1] = 2;
arr[2] = 3;
arr[3] = 4;
arr[4] = 5;

// Access Array elements
System.out.println(arr[2]); //Output 3

Arrays are suitable for scenarios where access to elements is high and fast access is required.

2. Linked List (LinkedList)
   A linked list is a data structure composed of nodes. Each node contains a data element and a pointer to the next node. The characteristic of a linked list is that elements can be inserted and deleted at any position, but accessing elements is less efficient.

// Create a linked list
LinkedList linkedList = new LinkedList();

// Add elements to the end of the linked list
linkedList.add ("Java");
linkedList.add("Python");
linkedList.add("C ");

// Access linked list elements
System.out.println( linkedList.get(1)); // Output Python

The linked list is suitable for scenarios where elements are frequently inserted and deleted.

3. Stack (Stack)
   The stack is a last-in-first-out (LIFO) data structure that can add and delete elements through push and pop operations.

// Create a stack
Stack stack = new Stack();

// Push to the stack
stack.push(1) ;
stack.push(2);
stack.push(3);

//Pop
int num = stack.pop();
System.out. println(num); // Output 3

The stack is suitable for scenarios where the order of elements needs to be reversed.

4. Queue (Queue)
   Queue is a first-in-first-out (FIFO) data structure, which can add and delete elements through add and remove operations.

// Create a queue
Queue queue = new LinkedList();

// Enter the queue
queue.add("Apple ");
queue.add("Banana");
queue.add("Orange");

// Dequeue
String fruit = queue.remove();
System.out.println(fruit); // The output Apple

queue is suitable for scenarios where elements need to be processed in order.

5. Hash table (HashMap)
   Hash table is a data structure that stores data in key-value pairs. It can quickly find the corresponding value based on the key.

//Create a hash table
HashMap map = new HashMap();

//Add key-value pairs
map.put("Alice", 25);
map.put("Bob", 30);
map.put("Catherine", 35);

// According to Key search value
int age = map.get("Bob");
System.out.println(age); // Output 30

The hash table is suitable for fast search, Scenarios for inserting and deleting elements.

Conclusion:
Choosing an appropriate data structure is very important to improve the efficiency of the algorithm and the readability of the code. By understanding the characteristics and application scenarios of arrays, linked lists, stacks, queues and hash tables, we can better choose the data structure that suits our project needs, and practice and learn through specific code examples.

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