how to add two numbers in c#

Question

1.40/5 (9 votes)

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Hi i am working on c# .net window application

i am unable to add two numbers

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace Add
{
    public partial class calci : Form
    {
        public calci()
        {
            InitializeComponent();
        }

        private void But_Add_Click(object sender, EventArgs e)
        {
          int a = Convert.ToInt32(Txt_1.Text );
          int b = Convert.ToInt32(Txt_2.Text);

            Ans.Text = a + b;
           

        }

    }
}

[edit]Code block added - OriginalGriff[/edit]

Posted 16-Jan-12 21:22pm

manoharnch

Updated 22-Jul-20 5:32am

VICK

v3

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Comments

Emre Ataseven 23-Apr-14 16:16pm

You need to read a C# for beginners book before starting to write code, blind coding is not a good way to improve yourself.

5 solutions

Solution 2

As you may easily find in the documentation[^], Convert.ToInt32 method may throw exceptions, hence you, as the wise developer should handle in your code such a possibility. See the sample code in the documentation.

Posted 16-Jan-12 21:41pm

CPallini

Solution 3

There is a control called NumericUpDown for Windows forms. Have a look at that. It will save you from overhead like conversion and validations.

Posted 16-Jan-12 21:42pm

dan!sh

Solution 5

If I modify you code, this should work:

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace Add
{
    public partial class calci : Form
    {
        public calci()
        {
            InitializeComponent();
        }

        private void But_Add_Click(object sender, EventArgs e)
        {
          int a = Convert.ToInt32(Txt_1.Text );
          int b = Convert.ToInt32(Txt_2.Text);
          int c = a + b;
          Ans.Text =  c.ToString();
        }

    }
}

Only change you need to do is:
1) check if numbers are not input and throw exception
2) convert added numbers to string to assign to textbox. I would like to take third variable 'c' to make this look good.

Posted 16-Jan-12 22:45pm

JP_Rocks

Comments

[no name] 18-Oct-19 8:40am

*spam redacted*

Solution 4

If you are converting the values to integer first then you have to store the output values in integer itself and then assign it to the textbox. that will be fine

C#

int c = a + b;

Ans.Text = c.ToString();

Posted 16-Jan-12 22:31pm

amolpatil2243

Updated 16-Jan-12 22:33pm

v2

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OriginalGriff · Accepted Answer · 2012-01-16T21:31:00

It's all going to depend on what your user types into the text boxes. If he types some invalid characters, then that code will not work. You also need to convert your number to a string in order to display it!
Try this:

C#

private void butAdd_Click(object sender, EventArgs e)
    {
    int a;
    int b;
    if (!int.TryParse(tbFirstNumber.Text, out a))
        {
        MessageBox.Show("I need just a number in the first box!");
        return;
        }
    if (!int.TryParse(tbSecondNumber.Text, out b))
        {
        MessageBox.Show("I need just a number in the second box!");
        return;
        }
    labAnswer.Text = (a + b).ToString();
    }