Creating A Class And Calling It From Main Program

This article tells you how to create your own class with some function in it and how to call these functions from the main function.

Creating your class

This is how my class mcCalculator looks. Its has five functions besides constructor and destructor, called Add, Subtract, Devide (that was a spelling mistake), Multiply, and DisplayOutVal. As you can see from their names, these functions add, subtract, multiply, and divide and store the results in a private variable iOutVal which is called by DisplayOutVal to display the results.

publicclass mcCalculator {
    privateint iOutVal;
    //Default constructor
    public mcCalculator() {
        iOutVal = 0;
    }
    public mcCalculator(int iVal1) {
            iOutVal = iVal1;
        }
        //destructor
        ~mcCalculator() {
            iOutVal = 0;
        }
    //methods
    publicvoid displayiOutVal() {
        Console.WriteLine("iOutVal = {0}", iOutVal);
    }
    // this function adds two values and saves in iOutVal
    publicvoid add(int iVal1, int iVal2) {
        iOutVal = iVal1 + iVal2;
    }
    // this function subtracts one from other and saves in iOutVal
    publicvoid subtract(int iVal1, int iVal2) {
        iOutVal = iVal1 - iVal2;
    }
    // this function multiplyies two values and saves in iOutVal
    publicvoid Multiply(int iVal1, int iVal2) {
        iOutVal = iVal1 * iVal2;
    }
    // this function devides one value from other and saves in iOutVal
    publicvoid Devide(int iVal1, int iVal2) {
        iOutVal = iVal1 / iVal2;
    }
}

Calling your class from Main

 

Now call mcCalculator from main. First create instance of mcCalculator and then call its member functions.

// Main Program
class mcStart {
    publicstaticvoid Main() {
        mcCalculator mcCal = new mcCalculator(50);
        mcCal.add(12, 23);
        mcCal.displayiOutVal();
        mcCal.subtract(24, 4);
        mcCal.displayiOutVal();
        mcCal.Multiply(12, 3);
        mcCal.displayiOutVal();
        mcCal.Devide(8, 2);
        mcCal.displayiOutVal();
    }
}

Don't forget to call using System as the first line of your file.

Quick Method

 

Download the attached file, second.cs, and run from command line, csc second.cs.