Change an integer value after a time interval ios - ios

Question

I am making a game with powerups. I have 3 powerups. When a powerup is active, I use an integer to identify which one it is, 1, 2, or 3, with 0 representing no active powerups. Once I activate a powerup, I want it to expire after a time interval, say 10 seconds. How do I reset the identifier integer back to 0?
For example, one powerup speeds up the ship. Here is my update method.
-(void) update:(ccTime)dt
{
if (powerupIdentifier == 0)
{
shipSpeed = 100;
}
if (powerupIdentifier == 1)
{
shipSpeed = 200;
}
CCArray* touches = [KKInput sharedInput].touches;
if ([touches count] == 1)
{
//MAKES SHIP MOVE TO TAP LOCATION
KKInput * input = [KKInput sharedInput];
CGPoint tap = [input locationOfAnyTouchInPhase:KKTouchPhaseBegan];
ship.position = ccp( ship.position.x, ship.position.y);
if (tap.x != 0 && tap.y != 0)
{
[ship stopAllActions]; // Nullifies previous actions
int addedx = tap.x - ship.position.x;
int addedy = tap.y - ship.position.y;
int squaredx = pow(addedx, 2);
int squaredy = pow(addedy, 2);
int addedSquares = squaredx + squaredy;
int distance = pow(addedSquares, 0.5);
[ship runAction: [CCMoveTo actionWithDuration:distance/shipSpeed position:tap]];//makes ship move at a constant speed
}
}
}

Answer 1

First, use an enum rather than an int.
typedef NS_ENUM(unsigned short, PowerUp) {
PowerUp_Level0,
PowerUp_Level1,
PowerUp_Level2,
PowerUp_Level3
};
Enum is far more readable, and is a lot more self-documenting then random integers.
Now, say we have a property:
#property (nonatomic, assign) PowerUp powerUp;
We can write a method to reset the power up:
- (void)resetPowerUp {
self.powerUp = PowerUp_Level0;
}
Now, when we've set it to some non-zero value and need to reset it (after 10 seconds), it's as simple as this:
self.powerUp = PowerUp_Level2;
[self performSelector:#selector(resetPowerUp) withObject:nil afterDelay:10.0f];