Calculator

Calculate expressions

Usage

When running the program, a dialog will show up informing you to input a expression. Then it will calculated the expression output the result.

If you want to stop the calculator, simply click 'cancel'

###Supported operators ####Binary Operators - plus(+) - minus(-) - multiplication(*) - division(/) - exponent(E) - power(^) - modulo(mod) - reminder(rem) - comma(,)

####Unary Operators

• negative(-)
• positive(+)
• logarithm(log)
• common logarithm(lg)
• natural logarithm(ln)

####Pair Operators

consumes a pair like log(2,8)

• logarithm(log)

####Suffix Operators

• Factorial(!)

###Format Just like common expressions. For example:

1+(2*3)^4*6
8e10-7e20
6mod5+2
(-1)*(1+23*3^2+(7+8)/7^3-21-13*3^2-21*3^2+(7+8)+23*3^2+(7+8)/7^3-21+23+(7+8)/7^3/7^3-21+23*3^2+(7+8)/7^3-2)
3+log(3,9)
lg7*lg8*lg9

Not supporting parentheses directly following a number like

2+3(5*6)

##Modify the code You may easily modify the code and add new operators ###Create a new operator For unary prefix operator, create a class which extends UnaryOperatorNode and register it in Registration.java by adding a line to register()

registerOperator("youroperatorname", YourOperatorClass.class, PREFIX);

And for binary operators, create a class which extends BinaryOperatorNode and register it with type BINARY instead of UNARY. ####Implementing Methods For example, this PlusOperatorNode

package com.github.rhacoal.calculator.operator.binaryoperator;

import com.github.rhacoal.calculator.exception.CalculationException;
import com.github.rhacoal.calculator.operator.BinaryOperatorNode;

import java.math.BigDecimal;

public class PlusOperatorNode extends BinaryOperatorNode {

    @Override
    public BigDecimal calculate() throws CalculationException {
        return getLeftChild().calculate().add(getRightChild().calculate());
    }

    @Override
    public int getPriority() {
        return 10;
    }
}

The getPriority() method implies what priority it should be. This affects the order of calculation. The calculate() method return the value of the current node by adding the value of two child nodes. ###Calculate expressions The class Calculation will help. Create an instance of Calculation class and call the method calculate(). It will return the result in java.math.BigDecimal. For example

System.out.println(new Calculation("1+2+3+4+5+6").calculate());