由于未捕获的异常“ NSInvalidArgumentException”而终止应用程序，原因：“-[NSDecimalNumber长度]：

Question

With these lines of code:

PayPalPayment *payment = [[PayPalPayment alloc] init];
NSLog(@"Price %@",[self.product objectForKey:@"Price"]);
NSString *string = [self.product objectForKey:@"Price"];
payment.amount = [[NSDecimalNumber alloc] initWithString:string];

my app is crashing with this log:

[NSDecimalNumber length]: unrecognized selector sent to instance

The NSLog is returning:

Price 96.67

Whay is it crashing???

Answer 1

I would guess that you have a type problem, most likely with the object at
[self.product objectForKey:@"Price"];
My guess is that this object is already an NSDecimalNumber , and when you treat it as a string and then call the initWithString method using it, bad things happen

put a breakpoint at:
payment.amount = [[NSDecimalNumber alloc] initWithString:string];

and then type po [string class] into the debugger.

This will show you the type of object stored at [self.product objectForKey:@"Price"];

Answer 2

It looks like your string object isn't an NSString . Looks like it's actually an NSDecimalNumber - set a breakpoint there and inspect the object. What kind of object is self.product ?