IsEven4

isEven4 is a utility function commonly found in programming libraries and collections of small algorithms. The function’s purpose is straightforward: it determines whether a given integer is even, returning a Boolean true if the number is divisible by two and false otherwise. The “4” in its name usually denotes a particular implementation or version, often indicating that it uses a bit‑shifting technique rather than the more traditional modulo operation. By evaluating the least significant bit of the input value—checking if that bit equals zero—the function can decide parity in a single very fast operation. This technique is especially advantageous in high‑performance contexts, such as embedded systems, game engines, or large‑scale numerical simulations, where even minor reductions in instruction count can lead to measurable speed gains.

Typical signatures in popular languages are:

- Java: public static boolean isEven4(int value) { return (value & 1) == 0; }

- Python: def is_even4(value): return (value & 1) == 0

- C: bool isEven4(int value) { return (value & 1) == 0; }

The function works correctly for all signed integer types, including negative numbers, because the least significant bit is set in two’s‑complement representation in the same way for negatives as for positives. It is fully portable across platforms that adhere to standard integer representations.

isEven4 is often cited in educational materials on bit manipulation, illustrating how low‑level operations can replace arithmetic while preserving correctness. Its simplicity also makes it a favorite in unit‑testing exercises and in performance benchmarks comparing modulo versus bitwise approaches.