Comparing Java's for(;;) and while(true) Loops and Their Generated Bytecode

The author discusses why many Java developers use for(;;) as an infinite loop, tracing its roots to C language syntax and noting that it avoids the magic constant 1 used in while(1) . Both forms are functionally equivalent, and personal preference often dictates which is chosen.

In Java, the author prefers while(true) but acknowledges that for(;;) is also common in projects. The article then examines whether there is any efficiency difference between the two constructs.

Using the Oracle/Sun JDK 8u (OpenJDK 8u) compiler, the following source snippets were compiled:

public void foo() {
    int i = 0;
    while (true) { i++; }
}

public void bar() {
    int i = 0;
    for (;;) { i++; }
}

The resulting bytecode for both methods is identical:

stack=1, locals=2, args_size=1
   0: iconst_0
   1: istore_1
   2: iinc          1, 1
   5: goto          2

Since the standard javac performs only minimal optimizations (constant folding and a few others), it generates the same bytecode for both loop forms. Consequently, any performance difference would have to arise later during interpretation or JIT compilation, where the input bytecode is identical.

Overall, the article concludes that the choice between for(;;) and while(true) is a matter of coding style rather than efficiency.