Java int to String - Integer.toString(i) vs new Integer(i).toString()

Understanding Efficiency: Why Integer.toString(i)?

Directness and memory efficiency are key when you need to convert an int to a String. Swift like a samurai's katana, Integer.toString(i) and String.valueOf(i) bypass the need for an intermediate Integer object, in contrast to using new Integer(i).toString(). No unnecessary stops or detours, Integer.toString(i) talks to the native method directly, serving up conversions both rapidly and efficiently.

Wearing Multiple Hats: String.valueOf(i)

String.valueOf(i) embodies versatility, able to juggle a variety of data types with deft ease. This function takes different inputs—integers, floats, objects, you name it—making it a consistent option for different data types. Hence, your code becomes more maintainable by relying on a common function call.

Keep It Simple: Integer + ""

Taking the road less traveled, i + "" can help pull off a quick conversion but risks raising eyebrows due to its unconventional nature. It smoothly rides the implicit StringBuilder usage but might leave your colleagues puzzled. Frequent use of this approach, particularly in loops or large-scale operations, might make your code look like a modern art piece—abstract, quirky, but potentially a performance nightmare

Drawbacks of Excess Object Creation

Unwanted object creation is like inviting party-crashers to your memory space—unwelcome and potentially damaging. Orchestrating a new Integer(i).toString() not only prepares a lonely Integer object party, but it kicks out the guest of honor as soon as the spotlight hits. It's akin to buying someone a birthday cake just to eat the candles—excessive and non-sensical.

Representation in Collections

There may be a rare scenario where you'd want Integer objects in a collection, operating in an object-oriented context for the sake of maintaining object identity. In such a case, using new Integer(i) might seem justified. However, bear in mind that auto-boxing often steps in to handle these conversions, eliminating such need in most cases.

Assessing Performance

Measured in the field, Integer.toString(i) is typically faster than creating a new Integer object. Performance tests, like those with OpenJDK's JMH (Java Microbenchmark Harness), confirm the wisdom in minimizing object creation for that extra speed boost. Remember, the quick brown fox outperforms the lazy object!

Consistent Coding Habits

It's no mystery that modern coding conventions advocate using static toString or valueOf methods over concatenation or manual object boxing. Why? Because this aligns with the principle of least astonishment, making your code easier to read and understand by other developers. Basically, don't play hide and seek with your code logic, be clear and make friends!