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In this guide, you will learn about the Arrays deepToString() method in Java programming and how to use it with an example.
1. Arrays deepToString() Method Overview
Definition:
The Arrays.deepToString() method returns a string representation of the "deep contents" of the specified array. It's useful for arrays that contain other arrays as their elements.
Syntax:
String deepToString(Object[] a)
Parameters:
- a: The array whose deep-content representation is to be returned.
Key Points:
- It can handle arrays that contain other arrays to multiple levels of depth.
- If an element is an array of a primitive type, it gets converted directly to a string.
- If an element is an array of objects, it uses deepToString() recursively.
- It returns "null" if the array is null.
- Throws ArrayStoreException if any array contains itself.
2. Arrays deepToString() Method Example
import java.util.Arrays;
public class DeepToStringExample {
public static void main(String[] args) {
int[][] matrix = {
{1, 2, 3},
{4, 5, 6},
{7, 8, 9}
};
String[] names = {"Alice", "Bob", "Charlie"};
Object[] mixedArray = {matrix, names, "Hello, World!"};
System.out.println("Matrix deep string representation: " + Arrays.deepToString(matrix));
System.out.println("Mixed array deep string representation: " + Arrays.deepToString(mixedArray));
}
}
Output:
Matrix deep string representation: [[1, 2, 3], [4, 5, 6], [7, 8, 9]] Mixed array deep string representation: [[[1, 2, 3], [4, 5, 6], [7, 8, 9]], [Alice, Bob, Charlie], Hello, World!]
Explanation:
The Arrays.deepToString() method is used to get a string representation of the deep contents of an array. In the example, we first convert a 2D integer array (matrix) to its string representation. Then, we create a mixed array containing the matrix, a string array, and a plain string. By using deepToString(), we can easily print nested arrays in a clear and formatted manner.
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