static NSDictionary* const letterValues = @{ ..... } in a method does not compile
You can only set a static variable during initialization with a constant. @{} creates an object, thus not a constant.
Do this instead:
- (void)awakeFromNib
{
[super awakeFromNib];
static NSDictionary* letterValues = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
letterValues = @{
@"A": @1,
@"B": @4,
@"C": @4,
// ...
@"X": @8,
@"Y": @3,
@"Z": @10,
};
});
...
}
Some other answers here suggest a check for nil instead of dispatch once, but that can cause issues when creating multiple tiles at the same time (via threads). dispatch_once implements the required locking.
You can use static, but the assignment can't be made on the same line. Try this:
- (void)awakeFromNib {
[super awakeFromNib];
static NSDictionary* letterValues = nil;
if (!letterValues) {
letterValues = @{@"A": @1,
@"B": @4,
@"C": @4,
// ...
@"X": @8,
@"Y": @3,
@"Z": @10};
}
...
}
The reason is that the @{<key> : <value>}
syntax is translated by the compiler into an Objective-C method ([[NSPlaceholderDictionary alloc] initWithObjects:forKeys:count:]
), which cannot be resolved at compile-time.
NSDictionary
objects can't be created at compile time. However, if you need a static object, you can create one. You can, for example, use the initialize
method, like this:
static NSDictionary* letterValues;
+ (void)initialize
{
if (self == [MyClass class]) {
letterValues = @{
@"A": @1,
@"B": @4,
@"C": @4,
@"X": @8,
@"Y": @3,
@"Z": @10,
};
}
}
The if statement is there to prevent multiple calls of your code in MyClass
subclasses.