Java floating-point type calculation

Java floating-point types need to use the JAVA.MATH.* Toolkit, so the results are what we want. Oh

1 ImportJava.math.BigDecimal;2 ImportJava.text.NumberFormat;3 4 5 /**6 * Mathematical Calculation class7  * @authorMingge8  *9  */Ten  Public classArithutil { One  A     PrivateArithutil () { -          -     } the      -     /** - * Floating-point addition -      * @paramNUM1 +      * @paramnum2 -      * @return +      */ A      Public Static DoubleAddDoubleNUM1,Doublenum2) { atBigDecimal v1=bigdecimal.valueof (NUM1); -BigDecimal v2=bigdecimal.valueof (num2); -         returnV1.add (v2). Doublevalue (); -     } -      -     /** in * Floating-point subtraction -      * @paramNUM1 to      * @paramnum2 +      * @return -      */ the      Public Static DoubleSubDoubleNUM1,Doublenum2) { *BigDecimal v1=bigdecimal.valueof (NUM1); $BigDecimal v2=bigdecimal.valueof (num2);Panax Notoginseng         returnv1.subtract (v2). Doublevalue (); -     } the      +     /** A * Two number multiplication the      * @paramNUM1 +      * @paramnum2 -      * @return $      */ $      Public Static DoubleMulDoubleNUM1,Doublenum2) { -BigDecimal v1=bigdecimal.valueof (NUM1); -BigDecimal v2=bigdecimal.valueof (num2); the         returnv1.multiply (v2). Doublevalue (); -     }Wuyi      the     /** - * Two number of divisions, except for endless rounding Wu      * @paramNUM1 -      * @paramnum2 About      * @param Scale $      * @return -      */ -      Public Static DoubleDivDoubleNUM1,DoubleNUM2,intScale ) { -         if(scale<0) { A             Throw NewIllegalArgumentException ("parameter exception ... "); +         } theBigDecimal v1=bigdecimal.valueof (NUM1); -BigDecimal v2=bigdecimal.valueof (num2); $         returnv1.divide (v2,scale,bigdecimal.round_half_up). Doublevalue (); the     } the      the      the     /** - * Reserved two decimal places in      * @return the      */ the      Public Static DoubleChangetwodecimal (Doubled) { AboutNumberFormat NF =numberformat.getnumberinstance (); theNf.setmaximumfractiondigits (2); the         returndouble.valueof (Nf.format (d)); the     } +  -     /** the * Retain the specified number of digitsBayi      * @paramD the      * @param Scale the      * @return -      */ -      Public Static DoubleChangedecimal (DoubleDintScale ) { theBigDecimal BG =NewBigDecimal (d); the         DoubleValue =Bg.setscale (scale, bigdecimal.round_half_up). Doublevalue (); the         returnvalue; the          -     } the      the      the     94      the      the      Public Static voidMain (string[] args) { theSystem.out.println (Arithutil.changetwodecimal (5.60));98System.out.println (Arithutil.changedecimal (6.356d, 5)); About     } -     101     102     103     104}

This tool class is temporarily written here, still need to continue to optimize ... Knowledge economy is a constant improvement.

Java floating-point type calculation