Just-In-Time (JIT)

Just-In-Time (JIT) compilation is a technique used in modern programming languages to improve execution speed by compiling code at runtime. Unlike traditional compilation, where source code is converted into machine code before execution, JIT compiles code dynamically while the program is running. This allows the system to optimize frequently used code paths based on the actual execution context, improving overall performance. JIT compilers translate intermediate code (such as bytecode) into native machine code specific to the host system. This process is typically carried out by virtual machines (e.g., Java’s JVM or .NET’s CLR). The major benefit of JIT compilation is that it eliminates the need to repeatedly interpret or recompile code, offering faster execution times after the initial compilation phase. Additionally, JIT can apply runtime optimizations like inlining, loop unrolling, and method specialization to make the program run more efficiently. This approach balances the flexibility of interpreted code with the performance of compiled code, making JIT a crucial component in high-performance environments.