Compile Time vs Runtime in Java

📚 Java Basics•📖 10 min read•beginner

Compile Time vs Runtime in Java

Difference between compile-time and runtime. Understand what happens during compilation and execution of a Java program.

Last updated: 15 January 2024

Compile Time

Who: Java Compiler (javac)
Input: Source code (.java)
Output: Bytecode (.class)
Errors: Syntax errors (missing semicolon, wrong type)

Runtime

Who: Java Virtual Machine (JVM)
Input: Bytecode (.class)
Output: Program execution
Errors: Runtime exceptions (DivByZero, NullPointer)

Process

Write: Main.java

Compile: javac Main.java -> Main.class