IF statement in Objective-C in Xcode - iphone

Question

In Xcode, I'm trying to make a button that changes it's text, relative to what the text currently is. For example: If the button says "1" and it is pressed, I want the text to change to "2" and "2" to "3" and so forth, here's the snippet of code that's giving me trouble:
if (magicButton.titleLabel = #"1") {
[magicButton setTitle:#"2" forState:UIControlStateNormal];
}
Xcode gives me this error "Assignment to readonly property" on line one of the snippet. I'm pretty new to Objective-C and iPhone App development, so maybe it's something crazily obvious and simple. Please don't mind if that's the case.
Here's a paste of my implementation file if it would help at all.
Thanks in advance.

Answer 1

'=' is for assignment while '==' is for comparison. But in the case of string comparison you should use isEqualToString method. Something like this:
if ([magicButton.titleLabel.text isEqualToString: #"1"]) {
[magicButton setTitle:#"2" forState:UIControlStateNormal];
}
PS. Also note that you should get the UILabel's text property

Answer 2

If you want to be changing the button text relative to what it is with no restrictions, you can't make a million if statements. You should get the value of the button title (if it even has a title) and just add 1 to it, like so:
NSString *string = randomButton.titleLabel.text;
if ([randomButton.titleLabel.text length] == 0) { //Check if there is not a title on the button
[randomButton setTitle:#"1" forState:UIControlStateNormal]; //And if there isn't, set it to "1"
}
else {
int yourInt = [string intValue]; //Convert to int
int nextInt = yourInt + 1; //Add one to value
NSString *finalString = [NSString stringWithFormat:#"%d",nextInt]; //Convert back to string
[randomButton setTitle:finalString forState:UIControlStateNormal]; //Finally set it as the title
}