Converting NSDecimalNumber to NSString

问题

I'm retrieving a key from an object that looks like this:

po obj
{
  TypeID = 3;
  TypeName = Asset;
}

The key value is being retrieved like this:

NSString *typeId = (NSString*)[obj objectForKey:@"TypeID"];

Rather than typeId being an NSString, it is an NSDecimalNumber. Why is that?

How do I convert it to an NSString?

回答1:

You need to use the stringWithFormat function:

NSString *typeId = [NSString stringWithFormat:@"%@", [obj objectForKey:@"TypeID"]];

or stringValue:

NSString *typeId = [[obj objectForKey:@"TypeID"] stringValue];

回答2:

This should work:

NSString *typeId = [[obj objectForKey:@"TypeID"] stringValue];

回答3:

If you want to get string value, just use "description". It works fine even if returned type is NSDecimalNumber, or NSString, or whatever:

NSString *typeId = [[obj objectForKey:@"TypeID"] description];

回答4:

Since this is the top search result and I don't see a question for NSDecimalNumber to String in Swift, here it is. This will show the localized decimal separator and all decimal places with a non-zero value.

let string = decimalNumber.description(withLocale: Locale.current)

回答5:

Use this to convert NSDecimalNumber to NSString:

NSDecimalNumber* dec1;
NSString* str;

str = dec1.stringValue;

Use this to convert NSString to NSDecimalNumber:

NSString* string1 = @"Stack overflow 123";
NSDecimalNumber* dec;

dec = (NSDecimalNumber *)string1;

来源：https://stackoverflow.com/questions/2573611/converting-nsdecimalnumber-to-nsstring