How to add to ammo if item collected sprite kit - sprite-kit

Question

i have a game where the guy runs around and collects stuff. So I want the score keeper to update and increase if he collects an item and decrease if he uses the item. For example, life item. so here is the code I got so far for labels but that works with text score not integers. any ideas? thanks
- (void)setupUI
{
int barHeight = 45;
CGSize backgroundSize = CGSizeMake(self.size.width, barHeight);
SKColor *backgroundColor = [SKColor colorWithWhite:10 alpha:50];
SKSpriteNode *hudBarBackground = [SKSpriteNode spriteNodeWithColor:backgroundColor size:backgroundSize];
hudBarBackground.position = CGPointMake(0, self.size.height - barHeight);
hudBarBackground.anchorPoint = CGPointZero;
[_hudLayerNode addChild:hudBarBackground];
// 1
SKLabelNode *scoreLabel = [SKLabelNode labelNodeWithFontNamed:#"AvenirNextCondensed-HeavyItalic"];
// 2
scoreLabel.fontSize = 20.0;
scoreLabel.text = #"Score: 0";
scoreLabel.name = #"scoreLabel";
scoreLabel.fontColor = [SKColor orangeColor];
// 3
scoreLabel.verticalAlignmentMode = SKLabelVerticalAlignmentModeCenter;
// 4
scoreLabel.position = CGPointMake(self.size.width - self.size.width / 4, self.size.height - scoreLabel.frame.size.height + 3);
// 5
[_hudLayerNode addChild:scoreLabel];
_scoreFlashAction = [SKAction sequence: #[[SKAction scaleTo:1.5 duration:0.1],
[SKAction scaleTo:1.0 duration:0.1]]];
[scoreLabel runAction: [SKAction repeatAction:_scoreFlashAction count:10]];
}

Answer 1

double score; //property
-(void)setupUI {
//...
SKAction *tempAction = [SKAction runBlock:^{
scoreLabel.text = [NSString stringWithFormat:#"Score: 3.0f", self.score];
}];
SKAction *waitAction = [SKAction waitForDuration:0.2];
[scoreLabel runAction:[SKAction repeatActionForever:[SKAction sequence:#[tempAction,waitAction]]]];
//...
}