"Use of unassigned local variable" error.

Agnel Fernando

I am very new to programming. I am doing my first project in C#.

I have declared two variables, "row"and "col" in the initial declaration step in main function. However the error of "use of unassigned local variable col" and "use of unassigned local variable row" is encountered in a particular for loop in my code. I do not know how to rectify it. I tried declaring col and row again inside the said for loop but then when i did so, it showed me an error that it is already declared in main.

Kindly help.

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Ranjit Powar10y ago
Accepted answer
In C#

Console.WriteLine("Row is {0} column is {1}",row,col);

You can use use Console.ReadKey() or Console.ReadLine() like getch() in C.

If it helps you, select it as correct answer.
+1
Ranjit Powar10y ago
Hi, please create new thread for new questions

Here is your answers
1. You can get all excel sheet data into data table as below

@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\temp\test.xls;" +
@"Extended Properties='Excel 8.0;HDR=Yes;'";
using(OleDbConnection connection = new OleDbConnection(con))
{
OleDbCommand command = new OleDbCommand("select * from [Sheet1$]", connection);
OleDbDataAdapter da = new OleDbDataAdapter(command);
DataTable dt=new DataTable();
da.Fill(dt);
}

For more information check
http://www.c-sharpcorner.com/blogs/get-all-sheets-from-excel-and-fill-data-of-selected-excel-sheet-in-datagridview

2. To write excel sheet check

http://www.gemboxsoftware.com/support/articles/read-write-excel-spreadsheet-net

https://bytescout.com/products/developer/spreadsheetsdk/read-write-excel.html

5. Yes you can create notepad and word files from C#

http://www.c-sharpcorner.com/UploadFile/mahesh/create-a-text-file-in-C-Sharp/

http://www.c-sharpcorner.com/UploadFile/muralidharan.d/how-to-create-word-document-using-C-Sharp/
0
Agnel Fernando10y ago
Hey..Thanks a lot Ranjit..!!! You are hitting the bull's eye every time. What you told me worked perfectly.

Now i have my next set of doubts:

I have data in the form of a 2D array in excel. This data i need to use in the code. That matrix would be my cost matrix. My questions are:

1. How to make the code read the number of rows and columns from the excel sheet?

2. How to extract/import data from the excel sheet into the program?

3. How to convert the excel data to a cost array c[i,j] ? ( because my entire code is based on the cost array only )

4. How to store the final cost array as an output excel sheet?

5. Is it possible to have output in the form of a text file or word file?
0
Agnel Fernando10y ago
That answer worked for me. Thanks a lot.
I have more doubts:
In c code we would use a statement to display row and column:
printf("Row is %d column is %d\n",row,col);
how do i replicate this statement in c#?

Also i have another doubt.
My code runs properly but the window vanishes before i am able to check the output. Is there any code to make the screen stay for sometime?
Or in other words is there a command like "getch();" in c# ?
0
Ranjit Powar10y ago
Hey before using variables, you must assign some value for them. Suppose you declare row and col variable as below

int row;
int col

Then before using these variables for further operations, you must assign some value to them as below

row=1;
col=1

If it helps you, select it as correct answer
+2