Can the JRE run Java programs?

Can the JRE run Java programs?

• A. Yes, but only after compiling.
• B. No.
• C. Yes, it can run Java programs.
• D. Only when bundled with the JDK.

Answer: (C)

The JRE's job is to run Java bytecode using the Java Virtual Machine. A Java program is written in source code, then compiled into bytecode by a compiler (which is part of the JDK). The JRE provides the runtime environment—the JVM and standard libraries—that execute that bytecode. So, yes, it can run Java programs, as long as those programs have already been compiled to bytecode. The JRE does not include a compiler, which is why you need the JDK to produce bytecode in the first place. You don’t need to bundle the JDK to run already-compiled programs; a standalone JRE is enough for execution.

The JRE's job is to run Java bytecode using the Java Virtual Machine. A Java program is written in source code, then compiled into bytecode by a compiler (which is part of the JDK). The JRE provides the runtime environment—the JVM and standard libraries—that execute that bytecode. So, yes, it can run Java programs, as long as those programs have already been compiled to bytecode. The JRE does not include a compiler, which is why you need the JDK to produce bytecode in the first place. You don’t need to bundle the JDK to run already-compiled programs; a standalone JRE is enough for execution.