Java Fundamentals Hardening the Introduction and overview of BigDecimal classes for 89:bigdecimal classes and the use of BigDecimal (subtraction)

1. BigDecimal class overview:

Since the float type and double are easy to lose precision when calculating. So in order to accurately express and calculate floating-point numbers, Java provides bigdecimal.

BigDecimal: A signed decimal number that is immutable and arbitrarily accurate.

2. BigDecimal Construction method

1  Public BigDecimal (String val)

3. use of BigDecimal (subtraction)

  1  public   BigDecimal Add (BigDecimal augend): Add  2   Public   BigDecimal subtract (BigDecimal subtrahend): minus  3  public   BigDecimal multiply ( BigDecimal divisor): Multiply  4  public  Span style= "color: #000000;" > BigDecimal divide (BigDecimal divisor): except  5  public  BigDecimal Divide (BigDecimal divisor, int  scale, int  roundingmode):  quotient, several decimals (scale), How to take (roundingmode)   

Code Demo:

1  Packagecn.itcast_02;2 3 ImportJava.math.BigDecimal;4 5 /*6 * Construction Method:7 * Public BigDecimal (String val)8  * 9 * Public BigDecimal Add (BigDecimal augend)Ten * Public BigDecimal Subtract (BigDecimal subtrahend) One * Public BigDecimal Multiply (BigDecimal multiplicand) A * Public BigDecimal Divide (BigDecimal divisor) - * Public BigDecimal Divide (BigDecimal divisor,int scale,int roundingmode): quotient, several decimals, how to take out -  */ the  Public classBigdecimaldemo { -      Public Static voidMain (string[] args) { -         //System.out.println (0.09 + 0.01); -         //System.out.println (1.0-0.32); +         //System.out.println (1.015 *); -         //System.out.println (1.301/100); +  ABigDecimal BD1 =NewBigDecimal ("0.09"); atBigDecimal Bd2 =NewBigDecimal ("0.01"); -System.out.println ("Add:" +Bd1.add (BD2)); -System.out.println ("-------------------"); -  -BigDecimal Bd3 =NewBigDecimal ("1.0"); -BigDecimal Bd4 =NewBigDecimal ("0.32"); inSystem.out.println ("Subtract:" +bd3.subtract (Bd4)); -System.out.println ("-------------------"); to  +BigDecimal Bd5 =NewBigDecimal ("1.015"); -BigDecimal Bd6 =NewBigDecimal ("100"); theSystem.out.println ("Multiply:" +bd5.multiply (Bd6)); *System.out.println ("-------------------"); $ Panax NotoginsengBigDecimal Bd7 =NewBigDecimal ("1.301"); -BigDecimal Bd8 =NewBigDecimal ("100"); theSystem.out.println ("Divide:" +bd7.divide (Bd8)); +System.out.println ("Divide:" A+ Bd7.divide (Bd8, 3, bigdecimal.round_half_up)); theSystem.out.println ("Divide:" ++ Bd7.divide (Bd8, 8, bigdecimal.round_half_up)); -     } $}

Operating effect:

Java Fundamentals Hardening the Introduction and overview of BigDecimal classes for 89:bigdecimal classes and the use of BigDecimal (subtraction)