我正在创建一个NSNumber
从字符串检查字符串是float
或int
使用NSNumberFormatter
。我想有一个方法来返回NSNumber
所持有的类型和正确的值。它适用于int
,但不适用于十进制数字。
NSNumber *n;
enum CFNumberType _numberType;
- (instancetype)initWithString:(NSString *)string {
self = [super init];
if (self) {
NSNumberFormatter *formatter = [NSNumberFormatter new];
decimalPattern = @"\\d+(\\.\\d+)";
if ([Utils matchString:string withPattern:decimalPattern]) {
// Float
formatter.numberStyle = NSNumberFormatterDecimalStyle;
_numberType = kCFNumberDoubleType;
n = [formatter numberFromString:string];
} else {
// Integer
formatter.numberStyle = NSNumberFormatterNoStyle;
_numberType = kCFNumberIntType;
n = [formatter numberFromString:string];
}
self = [self initWithNumber:n];
}
return self;
}
- (CFNumberType)value {
CFNumberType num; // How to determine the type of num?
CFNumberGetValue((CFNumberRef)n, _numberType, &num);
return num;
}
- (CFNumberType)numberType {
return _numberType;
}
在value
方法中,如果我指定float num
,那么它适用于浮点。但我不能使用float,因为我想让它也适用于int。这该怎么做?
我找到了解决方案。首先检查数字是否为double
并调用适当的值方法。
- (BOOL)isDouble {
if (_numberType == kCFNumberFloatType || _numberType == kCFNumberFloat32Type || _numberType == kCFNumberFloat64Type || _numberType == kCFNumberDoubleType) {
return YES;
}
return NO;
}
- (double)doubleValue {
if ([self isDouble]) {
return [n doubleValue];
}
return 0.0;
}
- (int)intValue {
if (![self isDouble]) {
return [n intValue];
}
return 0;
}