Correctly define and handle Java arrays

How to correctly define and operate arrays in Java

Array is a very commonly used data structure used to store a set of data of the same type. In Java, defining and manipulating arrays are very common operations. This article explains how to correctly define and manipulate arrays, with specific code examples.

1. Define an array

In Java, defining an array requires specifying the type and length of the array. The type of the array can be a basic data type or a reference type.

1. Definition of basic data type array

Use the keyword new to create an array object, and then specify the type and length of the array. For example, define an integer array intArray with a length of 5:

int[] intArray = new int[5];

2. Definition of reference type array

Reference type array can store references to objects. Also use the keyword new to create an array object, specifying the reference type and length. For example, define a string array strArray with a length of 3:

String[] strArray = new String[3];

2. Operation array

1. Assignment And accessing array elements

The elements of the array are accessed through subscripts, and the subscripts start from 0. You can use the equal sign (=) to assign values ​​to array elements, and you can also use the equal sign to assign the values ​​of array elements to other variables.

The example is as follows:

intArray[0] = 10; // Assign 10 to the first element of the array
int a = intArray[0]; // Assign the value of 10 to the first element of the array Assign the value of the first element to the variable a

strArray[1] = "Hello"; // Assign the value of the string "Hello" to the second element of the array
String str = strArray[1] ; //Assign the value of the second element of the array to the variable str

2. Traverse the array

Traversing the array is a common operation to access each element in the array. This can be achieved using a for loop or an enhanced for loop.

Example of using a for loop to traverse an array:

for(int i = 0; i

 System.out.println(intArray[i]);

}

Example of using an enhanced for loop to traverse an array:

for(int i : intArray){

 System.out.println(i);

}

3. Array properties and methods

There are some commonly used properties and methods in arrays, which can conveniently operate arrays.

Attributes of the array:

• length: Get the length of the array.

Array methods:

• toString(): Convert the array into a string.
• sort(): Sort the array.
• binarySearch(): Search for the specified element in the ordered array.
• equals(): Compares two arrays for equality.

The example is as follows:

int length = intArray.length; // Get the length of the array

String str = Arrays.toString(intArray); // Will Convert array to string

Arrays.sort(intArray); // Sort array

int index = Arrays.binarySearch(intArray, 5); // Search in ordered array Position of element 5

boolean equals = Arrays.equals(intArray1, intArray2); // Compare two arrays for equality

The above is the basic information on how to correctly define and operate arrays in Java and Example. Array is a very important data structure that is often used in Java programming. I hope this article will help you understand and use arrays.

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