What is the difference between a standard while(true) loop and for(;;)?
Is there any, or will both be mapped to the same bytecode after compiling?
Semantically, they're completely equivalent. It's a matter of taste, but I think while(true) looks cleaner, and is easier to read and understand at first glance. In Java neither of them causes compiler warnings.
At the bytecode level, it might depend on the compiler and the level of optimizations, but in principle the code emitted should be the same.
EDIT:
On my compiler, using the Bytecode Outline plugin,the bytecode for for(;;){} looks like this:
L0
LINENUMBER 6 L0
FRAME SAME
GOTO L0
And the bytecode for while(true){} looks like this:
L0
LINENUMBER 6 L0
FRAME SAME
GOTO L0
So yes, at least for me, they're identical.
It's up to you which one to use. Cause they are equals to compiler.
public class Test {
public static void main(String[] args) {
while (true) {
System.out.println("Hi");
}
}
}
javac -g:none Test.java
rename Test.class Test1.class
public class Test {
public static void main(String[] args) {
for (;;) {
System.out.println("Hi");
}
}
}
# javac -g:none Test.java
# mv Test.class Test2.class
# diff -s Test1.class Test2.class
Files Test1.class and Test2.class are identical
http://stackoverflow.com/questions/8880870/java-for-vs-whiletrue
本文探讨了Java中while(true)循环与for(;;)循环的差异。从语义上看两者完全等价,主要区别在于写作风格。通过编译后的字节码对比发现,两种循环结构在编译后的表现形式相同。因此,选择哪种循环结构更多取决于个人偏好。

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