🚀 6 Java Arrays Class Methods You’re Probably Underestimating

Ah, Java arrays. The OG of data structures in Java. Loved by some, feared by others, and misunderstood by many. If you’re still treating Java arrays like those stiff school uniforms you have to wear — it’s time for an upgrade.

Let me walk you through 6 super useful methods from Java’s Arrays class. These aren’t your grandma’s array tools. These are battle-tested, high-performance methods that do things like copying, sorting, filling, and even comparing arrays — because apparently, arrays have feelings too 😆.

Also, yes, these are all static methods. So no, you don’t need to instantiate the Arrays class like a rookie. Just use Arrays.methodName() and move on like a seasoned dev.

Let’s get into it. Buckle up. Some of these might just blow your mind… or at least mildly surprise you.

1. Arrays.asList() — Turning Arrays into Civilized Lists 🫱🪄

From caveman arrays to refined Java Lists in one line.

Have you ever stared at a plain array and wished it could do more? Like… maybe add and remove elements instead of just sitting there like a rock?

Well, enter Arrays.asList() — the glow-up your array deserves.

String[] lunch = {"chicken", "bacon", "avocado"};
List<String> menu = Arrays.asList(lunch);

Boom. Now it’s a List. But hold your horses 🐴 — it’s a fixed-size list backed by the original array. So don’t go trying to add or remove elements unless you’re ready for a UnsupportedOperationException and a developer existential crisis.

2. Arrays.fill() — Setting All Values Because You’re Lazy (and Efficient) 🖌️

Tired of for-loops just to initialize arrays? So is Java.

int[] scores = new int[5];  // Default: [0, 0, 0, 0, 0]
Arrays.fill(scores, 100);   // Now: [100, 100, 100, 100, 100]

Perfect if you’re building a game and everyone starts with 100 points. Or if you just want to feel powerful. No judgment.

3. Arrays.copyOf() — Because Assigning Arrays the “Normal” Way is a Trap ⚠️

Think array2 = array1 creates a new copy? That’s cute.

Reality check: You just made array2 point to the same memory as array1. Change one, and poof the other changes too. It’s a toxic relationship, really.

Use this instead:

int[] array1 = {1, 2, 3, 4, 5};
int[] array2 = Arrays.copyOf(array1, array1.length);

Now they’re two separate arrays. Therapy works.

4. Arrays.compare() — Not All Arrays Are Created Equal 📉📈

Want more than just a yes/no answer? Try this:

int result = Arrays.compare(array1, array2);

• 0 = equal
• < 0 = array1 is “smaller”
• > 0 = array2 is “smaller”

It compares lexicographically, which is a fancy word for “dictionary order.” Useful when sorting, filtering, or just trying to win an argument with another developer.

5. Arrays.sort() — Because You’re Too Cool for Bubble Sort 😎

Let’s be real — if you’re still manually sorting arrays in 2025, we need to talk. Unless you’re in a coding interview, please let Java do the heavy lifting:

int[] nums = {4, 2, 9, 1};
Arrays.sort(nums); // [1, 2, 4, 9]

Bonus: Sorting objects? Use a Comparator. Because Java won’t guess whether to sort students by name or GPA. That’s your job, buddy.

6. Arrays.binarySearch() — Quick, But High Maintenance 🔍

Want to find the index of a value fast?

int index = Arrays.binarySearch(nums, 9);  // returns 3

⚠️ BUT your array must be sorted. If not, this method becomes totally unreliable — like that one friend who always says they’re “5 minutes away.”

Also, if your array has duplicate values? It’ll return a matching index, but don’t bet on which one. Just know it found something. Somewhere.

Final Thoughts: Use the Built-ins. Your Future Self Will Thank You 🙏

Could you write your own version of equals() or binarySearch()? Absolutely.

Should you? Probably not.

Java’s built-in methods are optimized, tested, and generally smarter than most of us before coffee. Use them. Trust them. And stop reinventing the wheel unless you’re building a car from scratch 🚗.

If you found this helpful, confusing, or mildly entertaining — give it a clap 💚 and drop your thoughts below.

Until next time, keep coding, and don’t forget to sort before searching. Java remembers. 😅