Format Float to n decimal places

##"); // 2 decimal places df.setRoundingMode(RoundingMode.CEILING); String formatted = df.format(value);

In the clash of titans, they both trim to **2 places**: `String.format()` is like QuickSilver while `DecimalFormat` is like Thor wielding **rounding modes**.

## Going beyond basics // Let the games begin

`String.format()` is your ninja protecting the **integrity** of your float values, keeping them safe from transforming into a double. This method is like a gatekeeper ensuring your data type stays a float, holding the **precision** charm.

On the other hand, `DecimalFormat` is a sorcerer who not only formats the value, but also lays different **rounding enchantments**. Remember, '#' in the pattern is like a cloaking device, it can hide the digit if it's zero. "Magic, right?"

Staying away from BigDecimal for routine formatting tasks is like avoiding the mad titan Thanos - it saves resources. BigDecimal is like a celestial being meant for high-precision calculations, and is an **overkill** for common needs.

## The Magic of Rounding and Locale // Wizardly Maddening 

`BigDecimal`, with its mighty `setScale()`, coupled with a rounding spell like `ROUND_HALF_UP`, is your trusted wizard to format and round a float with **exceptional precision**.

For **globetrotters**, use `NumberFormat`. It adheres to different numeral systems and decimal separators of locales. This is the masterstroke for universal applications. You can dictate the number of decimal places using `setMaximumFractionDigits()` and `setMinimumFractionDigits()`.

When formatting floats on a global stage, the Djinn `NumberFormat` should accompany you. Alas, avoid summoning `DecimalFormat` directly, use the magic lamp, I mean the factory methods provided by `NumberFormat`.

## The power of Symbols // Advanced wizardry 

`DecimalFormat` is your master glyph maker. Their symbols `0`, `#`, `.`, and `,` in patterns let you dictate **exact format structure**, including grouping separators. They are your runes for financial applications, where precise formatting is a mandate.

In the mystical world of Java, always refer to the **ancient scrolls - aka official Java documentation** for detailed understanding of these glyphs and their usage.

## Exceptions, Pitfalls and how to conquer them // The grand battle 

Formatting floats is like venturing into a magical land. Be mentally prepared for the creatures - **limitations** inherent to floating-point numbers. Some decimal values are like shape-shifters and cannot be represented exactly. Beware of these beasts that could lead to rounding errors.

Test your spells with known cases like `Float.MIN_VALUE`, `Float.MAX_VALUE`, and minuscule differences between numbers. If precision is of paramount importance and you cannot tolerate these shape-shifters, consider invoking high-precision libraries or convert your brave float values into **wise strings**.

## Speed, Concurrency and a little bit of sparkle // Race to the throne

`String.format()` and `DecimalFormat` are your greyhounds - fast and useful. If you're engaging in a marathon, evaluate the **performance quotient** - use optimized methods like custom string builders or alternative libraries. For high-speed requirements, consider compacting your `DecimalFormat` scrolls.

Working with a dragon's hoard of data? Consistent formatting is the key, folks. Pool formatter instances or use thread-local storage patterns to lessen overheads and speed up your multi-threaded systems.