Objective C - XCode not recognizing variable outsi

问题:

Trying to set a sprite filename with an if statement, then load the proper file based on that string. It looks like there's a problem with my variable scope, but I don't know what it is.

Here's my code:

if ([[GameManager sharedGameManager] newHighScore] == TRUE) {
    NSString *highScoreLabelText = @"label-new-high-score.png"
} else {
    NSString *highScoreLabelText = @"label-high-score.png"
}

CCSprite *highScoreLabel = [CCSprite spriteWithSpriteFrameName:highScoreLabelText];
[highScoreLabel setAnchorPoint:ccp(0,0)];
[highScoreLabel setPosition:ccp(20, winSize.height * 0.575f)];
[self addChild:highScoreLabel];

XCode is flagging an error, saying that highScoreLabelText is an undeclared identifier, and thus won't compile the app. Do I need to declare something else along with the NSString to get the rest of the code to work with the variable?

回答1:

This is because you declared two separate inner-scope variables in both branches of if. Neither of these two variables is visible outside its scope, so you are getting an error.

You should move the declaration out of if, like this:

NSString *highScoreLabelText;
if ([[GameManager sharedGameManager] newHighScore] == TRUE) {
    highScoreLabelText = @"label-new-high-score.png"
} else {
    highScoreLabelText = @"label-high-score.png"
}

Now highScoreLabelText is visible outside of your if statement.

回答2:

Declare the local variable outside the if-else statement