Sum Of textboxes values

Question

this is my code

int sum = int.Parse(TextBox5.Text) + int.Parse(TextBox6.Text) + int.Parse(TextBox7.Text);

Label1.Text = String.Format("{0}", sum);

when I enter all three textboxes it runs clearly but if i keep any one or two of them null it gives error...

input was not in correct formate ..

how can I solve this error.....

Satyapriya Nayak · Answer

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace Add { public partial class Form2 : Form { public Form2() { InitializeComponent(); } private void btnadd_Click(object sender EventArgs e) { int i jk; int.TryParse(textBox1.Text out i); int.TryParse(textBox2.Text out j); int.TryParse(textBox3.Text out k); int result = i + j + k; label1.Text = result.ToString(); } } }

Srinubabu Ravilla · Answer

Try this int val1; int val2; int val3; int.TryParse(TextBox5.Text out val1); int.TryParse(TextBox6.Text out val2); int.TryParse(TextBox7.Text out val3); Label1.Text = String.Format({0} val1+val2+val3);

Shankar M · Answer

Hi Saurabh int.TryParse Method tries to convert the given Input to a number returning a boolean (true/false) value. If the return value is true - It is a valid Number If the return equals to false - The Input is not a number  that is Invalid. Please try this using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace PerformAdd { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender EventArgs e) { int result; bool validInput = int.TryParse(textBox1.Text out result); if (!int.TryParse(textBox1.Text out result)) { MessageBox.Show(Invalid Input TextBox1); } else if (!int.TryParse(textBox2.Text out result)) { MessageBox.Show(Invalid Input TextBox2); } else if (!int.TryParse(textBox3.Text out result)) { MessageBox.Show(Invalid Input TextBox3); } else { int x = Convert.ToInt16(textBox1.Text); int y = Convert.ToInt16(textBox2.Text); int z = Convert.ToInt16(textBox3.Text); int SumofInputs = x + y + z; label1.Text = SumofInputs.ToString(); } } } } Regards Shankar M

Gajendra Yadav · Answer

You are getting this error because you are trying to convert string type to integer type. by default textbox contains empty string( ) that can not be converted to int type. Before sum do validation if textbox is not emty the add this. or You Use int.TryParse() method instead of int.Parse or convert.Toint32 method. I hope it will help you

Shankar M · Answer

Hi Saurabh It is best Practise to use int.TryParse method. Please view this link http://www.homeandlearn.co.uk/csharp/csharp_s3p9.html T hanks & Regards Shankar M