Arrays Utility Class in Java.

Java mein agar aap arrays ke saath kaam kar rahe ho, toh java.util.Arrays class aapka kaafi kaam aasaan bana deti hai. Isme aise kaafi saare built-in methods hote hain jo aapko sorting, searching, comparing, converting jaise kaam without manual logic karne deti hain.

Chaliye step-by-step is class ke features ko samjhte hai with practical example.

Arrays Class kiya hoti hai

Java ke java.util.Arrays class ek utility class hai jo aapko arrays ke upar operations karne ke liye static methods provide karti hai. Isse aapko manually loops likhne ki zarurat nahi padti.

import java.util.Arrays; // Import karna zaroori hai

Common Methods of Arrays Class

1. Array Print karna – toString()

Normally agar aap array ko print karte ho, toh wo kuch ajeeb format mein aata hai. Jaise:

int[] arr = {1, 2, 3};
System.out.println(arr); 

Output:

[I@15db9742  // Yeh samajh nahi aata

Lekin Arrays.toString() use karoge toh:

int[] arr = {1, 2, 3};
System.out.println(Arrays.toString(arr));

Output:

[1, 2, 3]

To string ka use kabhi bhi array ko easily readable format mein dikhane ke liye hota hai.

2. Array ko Sort Karna – sort()

Arrays class ka ye method Array ko Ascending Order mein sort kar deta hai:

int[] marks = {45, 22, 89, 10};
Arrays.sort(marks);
System.out.println(Arrays.toString(marks));

Output:

[10, 22, 45, 89]

Ye method strings ya characters bhi sort ho sakte hain:

String[] names = {"Zara", "Aman", "Neha"};
Arrays.sort(names);
System.out.println(Arrays.toString(names));

Output:

[Aman, Neha, Zara]

3. Binary Search – binarySearch()

Yeh method sorted array pe hi kaam karta hai. Agar element milta hai toh uska index return karega, warna negative value.

int[] data = {5, 10, 15, 20, 25};
int index = Arrays.binarySearch(data, 15);
System.out.println("Index: " + index);

Output:

Index: 2

Note: Array pehle sorted hona chahiye warna wrong result milega.

4. Arrays Equal Hai ya Nahi – equals()

Ye method ye check karta hai ki two arrays ki values same hai ya nahi ye boolean value return karta hai hai.

int[] a = {1, 2, 3};
int[] b = {1, 2, 3};
System.out.println(Arrays.equals(a, b));

Output:

true

Agar ek bhi element different hoga toh false return karega otherwise true.

5. Array Fill Karna – fill()

Jab hame kisi Array ke saare elements ko kisi ek particular value se fill karna hota hai to ham is method ka use karte hai kioki ye array ke har element ko kisi ek particular value se fill karta hai:

int[] arr = new int[5];
Arrays.fill(arr, 100);
System.out.println(Arrays.toString(arr));

Output:

[100, 100, 100, 100, 100]

6. Array Copy Karna – copyOf() aur copyOfRange()

int[] original = {1, 2, 3, 4};
int[] copy = Arrays.copyOf(original, 6);
System.out.println(Arrays.toString(copy));

Output:

[1, 2, 3, 4, 0, 0]

Extra elements 0 se fill ho jaate hain.

int[] part = Arrays.copyOfRange(original, 1, 3);
System.out.println(Arrays.toString(part));

Output:

[2, 3]

7. Converting Arrays to List – asList()

String[] fruits = {"Apple", "Banana", "Mango"};
List<String> list = Arrays.asList(fruits);
System.out.println(list);

Output:

[Apple, Banana, Mango]

Ye list fixed-size hoti hai, add/remove nahi kar sakte.

Must-Use Methods Recap:

• toString() – Print karne ke liye
• sort() – Sorting ke liye
• binarySearch() – Fast searching
• equals() – Compare arrays
• fill() – Values set karne ke liye
• copyOf() – Clone ya resize karne ke liye