将指数编号转换为nsnumber

Question

我无法将指数号码（如9.471347923322231e + 18）转换为nsnumber。有没有人知道如何做到反过来？感谢。

Answer 1

对于指数，你应该使用：

NSDecimalNumber *number = [NSDecimalNumber decimalNumberWithMantissa:12345
                                       exponent:-3
                                       isNegative:YES];

或者如果你想从NSString中获取它：

+ (NSDecimalNumber *)decimalNumberWithString:(NSString *)numericString locale:(NSDictionary *)locale;

例如：

NSString *stringNumber = @"9.471347923322231e+18";
NSDictionary    *locale = [NSDictionary dictionaryWithObject:@"." forKey:NSLocaleDecimalSeparator];
NSDecimalNumber *number = [NSDecimalNumber decimalNumberWithString:stringNumber locale:locale];