//NSDecimalNumber是NSNumber的子类，是苹果针对浮点型计算时存在精度计算误差的问题而提供
的一个类
计算相关
NSString *str1 = @"100.90";
NSString *str2 = @"100.09";
NSDecimalNumber *decimal1 = [NSDecimalNumber decimalNumberWithString:str1];
NSDecimalNumber *decimal2 = [NSDecimalNumber decimalNumberWithString:str2];
//加
NSDecimalNumber *addDecimal = [decimal1 decimalNumberByAdding:decimal2];
NSLog(@"%@",addDecimal);
//减
NSDecimalNumber *subtractDecimal = [decimal1 decimalNumberBySubtracting:decimal2];
NSLog(@"%@",subtractDecimal);
//乘
NSDecimalNumber *multiplyDeciaml = [decimal1 decimalNumberByMultiplyingBy:decimal2];
NSLog(@"%@",multiplyDeciaml);
//除
NSDecimalNumber *dividDecimal = [decimal1 decimalNumberByDividingBy:decimal2];
NSLog(@"%@",dividDecimal);
//次方运算
NSDecimalNumber *raisingDecimal = [decimal1 decimalNumberByRaisingToPower:0];
NSLog(@"%@",raisingDecimal);
//10次方
NSDecimalNumber *multiplyingByPowerOf10Decimal = [decimal1 decimalNumberByRaisingToPower:10];
NSLog(@"%@",multiplyingByPowerOf10Decimal);
NSString和double转换
/*
*double －－－> NSString
*/
- (NSString *)decimalNumberWithDouble:(double)conversionValue {
NSString *doubleString = [NSString stringWithFormat:@"%lf",conversionValue];
NSDecimalNumber *decNumber = [NSDecimalNumber decimalNumberWithString:doubleString];
return [decNumber stringValue];
}
/*
*NSString －－－> double
*/
- (double)StringChangeToDoubleForJingdu:(NSString *)textString {
if (textString == nil || [textString isEqualToString:@""]) {
return 0.0;
}
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
return [[formatter numberFromString:textString]doubleValue];
}
