如何在xcode中反转for()循环？

Question

我试图在xcode中反转for循环.

for (enemyBullet *b in bullets)
{

}

有人可以帮忙吗？

谢谢

Answer 1

Perspx的方式不会使用快速对象枚举.你真正想做的是:

NSEnumerator *bulletReverseObjectEnumerator = [bullets reverseObjectEnumerator];
for (enemyBullet *b in bulletReverseObjectEnumerator) {
   NSLog(@"DANCE BULLET DANCE: %@", b);
}

概念是,快速对象枚举比使用平坦的while循环迭代快几倍.

Answer 2

NSEnumerator *enu = [bullets reverseObjectEnumerator];

enemyBullet *b = nil;

while (b = [enu nextObject]) {
    // do your stuff here
}