java code to evaluate a arithmetic expression....

Java code to evaluate in arithmetic expression......

following order...
Division
Multiplication
Subtraction
Addition

The code: -

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public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        String a = "4-6-1+3*9/2"; //1*3+2*7-1-1
        String[] b = null;
        String c = null;
        //double[] d =null;
        Main obj = new Main();
        //double d1 = 0;
        System.out.println(obj.check(a));
        /*b = obj.mul (a);
        //a = b[0].substring(0, b[1].length()-1) + func2(func3(b[0].trim()), b[1]).toString() + b[]
        System.out.println(b[0].substring(obj.last(b[0])+1, b[0].length()));
        System.out.println(b[1].substring(0, obj.first(b[1])));
        c = obj.mult(b[0].substring(obj.last(b[0])+1, b[0].length()), b[1].substring(0, obj.first(b[1])));
        System.out.println(d1);
       
        a = b[0].substring(0, obj.last(b[0])+1) +d1 + b[1].substring( obj.first(b[1]), b[1].length());
        System.out.println("The string is: " + a);
       
       
        //System.out.print(func2(b[0].substring(0, func3(b[0].trim())), b[1].substring(func4(b[1].trim()), ));
        for(int i=0; i<b.length; i++)
            System.out.println(b[i]);
        
        //System.out.println(b[1].substring(0,b[1].indexOf('+')));
       
        //String f = b[1].substring(0,b[1].indexOf('+'));
       
        //d1 = obj.func2(b[0], f);
        System.out.println("The addition: " + d1);*/
    }
    double func(String a) {
        double d = 0;
       
        return d;
    }
    String mult(String a, String b) {
        double c = func1(a) * func1(b);       
        return (Double.toString(c));
    }
    String minus(String a, String b) {
       
        double c = func1(a) - func1(b);
        System.out.println(c);
        return (Double.toString(c));
    }
    String add(String a, String b) {
        double c = func1(a) + func1(b);
        return (Double.toString(c));
    }
   
    String divide(String a, String b) {
        double c = func1(a) / func1(b);
        return (Double.toString(c));
    }
   
    double func1(String a) {
        double d =0;
        try {
            d = Double.parseDouble(a);
        } catch (NumberFormatException n1) {
            System.out.println(n1);
        }
        return d;
    }
    /*String[] mul(String a) {
        String[] b = null;
        b = a.split("\\*");
        return b;
    }
    double mul1(String[] a) {
        double c = 0;
        try{
           
        } catch()
        return c;
    }*/
    /*int last(String a) {
        int c=0;
        char d;
        for(int i =a.length()-1; i>0; i=i-1) {
            if(a.charAt(i)=='+' || a.charAt(i)=='-' || a.charAt(i)=='*' || a.charAt(i)=='/')
            return i;
        }
        return c;
    }
    int first(String a) {
        int i=0;
        for(i =0; i<a.length(); ++i) {
            if(a.charAt(i)=='+' || a.charAt(i)=='-' || a.charAt(i)=='*' || a.charAt(i)=='/')
            return i;
        }
        return i;
    }*/
    String check(String a) {
        String[] b=null;
        if(a.contains("+")) {
            //System.out.println("This is inside minus");
            b = a.split("\\+",2);
           
            a=add(check1(b[0]),check(b[1])) ;
            return a;
        }
        else
            return check1(a);
    }

    private String check1(String a) {
       
        String[] b=null;
        //System.out.println(a);
        if(a.contains("-")) {
            //System.out.println("This is inside minus");
            /*if(a.indexOf('-')!=0) {
                b = a.split("\\-",2);
            b[1] = "-" + b[1];
            a = add(check2(b[0]), check1(b[1])) ;
            }
            else {
                a = add(check2(b[0]), b[1]) ;
            }*/
            if(a.indexOf('-')==0)
            {
                a =a.substring(1);
                if( a.contains("-")) {
                    b = a.split("-", 2);
                    b[0] = "-" + b[0];
                    b[1] = "-" + b[1];
                    a = add(check2(b[0]), check1(b[1]));
                }
                else
                    a = "-"+a;
            } else {
                b = a.split("-", 2);
                //b[0] = "-" + b[0];

                b[1] = "-" + b[1];
                a = add(check2(b[0]), check1(b[1]));
            } 
            return a;
        }else
            return check2(a);
        //throw new UnsupportedOperationException("Not yet implemented");
       
    }

    private String check2(String a) {
        String[] b=null;
        if(a.contains("*")) {
            b = a.split("\\*",2);
            a = mult(check3(b[0]), check2(b[1])) ;
            return a;
        }
           
        else
            return check3(a);
        //throw new UnsupportedOperationException("Not yet implemented");
    }

    private String check3(String a) {
        String[] b=null;
        if(a.contains("/")) {
            b = a.split("\\/");
            a = divide(b[0], check3(b[1])) ;
            return a;
        }
           
        else
            return a;
        //throw new UnsupportedOperationException("Not yet implemented");
    }
}

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Reply any comments or suggestions.......

Thanks....

--
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