简介

丰富而灵活的数学表达式解析器（表达式评估器） ，以纯文本/字符串形式提供的表达式），用于JAVA和C＃。主要功能：丰富的运算符内置库，常量，常量等

代码片段

 // 计算最小值
        Argument days = new Argument("days = 30");
        Expression min = new Expression("min(days/10,1)", days);
        mXparser.consolePrint("30/10 与1 的更小值:" + min.getExpressionString() + "----" + min.calculate() +"\n");
        //表达式
        Expression e = new Expression("2-(32-4)/(23+4/5)-(2-4)*(4+6-98.2)+4");
        mXparser.consolePrintln("表达式: " + e.getExpressionString() + " = " + e.calculate());
        //绝对值
        Expression abs = new Expression("abs(-1)");
        mXparser.consolePrintln("Res: " + abs.getExpressionString() + " = " + abs.calculate());
        //开方
        Expression sqrt = new Expression("sqrt(2)");
        mXparser.consolePrintln("Res: " + sqrt.getExpressionString() + " = " + sqrt.calculate());
        //函数
        Function A = new Function("t(a,b) = 1/2 * a *b");
        Expression expression = new Expression("t(2,4)", A);
        mXparser.consolePrintln(expression.getExpressionString() + "-----------" + expression.calculate());
        //参数
        Argument a = new Argument("a = 3");
        Argument b = new Argument("b = 3");
        Argument h = new Argument("h = 4");
        Expression expression1 = new Expression("t(b,h)", A, b, h, a);
        mXparser.consolePrintln(expression1.getExpressionString() + "-----------" + expression1.calculate());
        Expression expression2 = new Expression("1/2 * a *b", A, b, h, a);
        mXparser.consolePrintln(expression2.getExpressionString() + "-----------" + expression2.calculate());
        //除法 乘法
        Expression expression3 = new Expression("2/3*3");
        System.out.println("计算结果集-------->" + expression3.calculate());

运行结果

[mXparser-v.4.4.2 bin JDK 8] 30/10 与1 的更小值:min(days/10,1)----1.0
表达式: 2-(32-4)/(23+4/5)-(2-4)*(4+6-98.2)+4 = -171.57647058823528
[mXparser-v.4.4.2 bin JDK 8] Res: abs(-1) = 1.0
[mXparser-v.4.4.2 bin JDK 8] Res: sqrt(2) = 1.4142135623730951
[mXparser-v.4.4.2 bin JDK 8] t(2,4)-----------4.0
[mXparser-v.4.4.2 bin JDK 8] t(b,h)-----------6.0
[mXparser-v.4.4.2 bin JDK 8] 1/2 * a *b-----------4.5
[mXparser-v.4.4.2 bin JDK 8] 计算结果集-------->2.0

依赖

 <dependency>
            <groupId>org.mariuszgromada.math</groupId>
            <artifactId>MathParser.org-mXparser</artifactId>
            <version>4.4.2</version>
        </dependency>