What do two semicolons mean in Java for loop? [duplicate]
I was looking inside the AtomicInteger
Class开发者_运维技巧 and I came across the following method:
/**
* Atomically increments by one the current value.
*
* @return the previous value
*/
public final int getAndIncrement() {
for (;;) {
int current = get();
int next = current + 1;
if (compareAndSet(current, next))
return current;
}
}
Can someone explain what for(;;)
means?
It is equivalent to while(true)
.
A for-loop has three elements:
- initializer
- condition (or termination expression)
- increment expression
for(;;)
is not setting any of them, making it an endless loop.
Reference: The for statement
It's the same thing as
while(true) {
//do something
}
...just a little bit less clear.
Notice that the loop will exit if compareAndSet(current, next)
will evaluate as true
.
It's just another variation of an infinite loop, just as while(true){}
is.
That is a for ever loop. it is just a loop with no defined conditions to break out.
It's an infinite loop, like while(true)
.
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