Trouble with lilstbox and arrays

Question

Hi All
I have a listbox with a list like below

1. 05/7/11</TD><TD><spanclass=/>John</TD><TD><spanclass=/>
2. 05/07/11</TD><TD><spanclass=/>Tena</TD><TD><spanclass=/>
3. 09/8/11</TD><TD><spanclass=/>Larry</TD><TD><spanclass=/>
4. 05/11/11</TD><TD><spanclass=/>Glenda</TD><TD><spanclass=/>

Using the code below that shuld check for a single digit month

string regExp1 = "(?<Month>\\d{1,2})/(?<Day>\\d{1})/(?<Year>(?:\\d{4}|\\d{2})).*";
string arr;
for (int a = 0; a < 99; i++)
{
 arr = arrStrUSA[a];
 if (arr == regExp1)
 {
 arr.Insert(4, "0");
 listBox2.Items.Add(arr);
 }
 else
 {
 listBox2.Items.Add(arr);
 }
}

I thought I could iterate through the listbox adding a 0 to the front of the ones with a single digit for a month but nothing comes.
What I need to do is add 0 to line 1, 3 so they look like lines 2, 4
then delete "</TD><TD><spanclass=/>"

Thanks in advance

Mike

theLizard · Answer

Vulpes is correct I used an array of strings for my example code I did not test using a listBox1 so as Vulpes says ToString() is needed.

Vulpes · Answer

The problem is that listBox1.Items[i] returns an object not a string. You therefore need to replace this expression wherever it occurs with listBox1.Items[i].ToString() to avoid the errors.

MIke Lumley · Answer

Hi I keep getting 7 errors saying : 'object' does not contain a definition for 'Substring' and no extension method 'Substring' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?) I've got these for the referance : 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; using System.Text.RegularExpressions; Am I missing something out because both your code looks like it would work!!!Ahhhh Thanks Mike

theLizard · Answer

If the items in list box 1 are consistent (as you have shown) then the following will give you what you want you don't need to use replace or insert just do it. listBox1.Items.Add(05/7/11 John ); listBox1.Items.Add(05/11/11 Sara ); private void button1_Click(object sender EventArgs e) { //assuming that each item in the list box begins with the date you are wanting to move to listbox2 //and the format is as per your example then the following code will do what you are after. //notice that I am not inserting or replacing anything just doing the job that needs to be done. DateTime t; string name; for (int i = 0; i { //first get the string beginning with the name ( Glenda ) to the end of the string name = listBox1.Items[i].Substring(listBox1.Items[i].IndexOf(=/>) + 3); //discard everything past the name from the first occurrence of  name = name.Substring(0 name.IndexOf( //now get the date part by extracting the string from pos 0 to the first occurrence of  t = DateTime.Parse(listBox1.Items[i].Substring(0 listBox1.Items[i].IndexOf( //Now add to list box 2 listBox2.Items.Add(t.ToString(dd/MM/yy) + + name); //or can be don in one go listBox2.Items.Add(((DateTime)t = DateTime.Parse(listBox1.Items[i].Substring(0 listBox1.Items[i].IndexOf( } }

MIke Lumley · Answer

Hi sorry back now I have a listbox with lines looking like this: 05/9/11 Glenda And would like them to look like: 05/09/11Glenda If I can get a 6 digit date I can delete every thing else also if I use: string21.Insert(10 a); why does it go in at number 3 I'm a bit lost Thanks in advance Mike

theLizard · Answer

I would have thought that since the OP only wants the date part of the string it would be better to treat it as a date from the start. If it is known that the start of the list item to the first  Casting the substring to a DateTime then formatting is gauranteed to return the date string in the final format that you want regardless of region. i.e. dd/MM/yy dd/MMM/yy dd/MM/yyyy ddd d MM yyyy can't get simpler than this listBox1.Items.Add(((DateTime)t = DateTime.Parse(s[i].Substring(0 s[i].IndexOf( I like simple it it keeps programs simple and makes them more efficient with less overheads. Cheers

Vulpes · Answer

Yes there are several ways to do this without using regular expressions. Perhaps the easiest way of all is this one: for (int a = 0; a { arr = listBox1.Items[a].ToString(); if( arr[4] == /) { arr = arr.Insert(3 0); } arr = arr.Replace(  ); listBox2.Items.Add(arr); }

theLizard · Answer

string[] s = new string[4]; s[0] = 05/7/11 John ; s[1] = 05/11/11 Sara ; s[3] =  09/8/11 Larry ; s[4] =  05/11/11 Glenda ; //assuming that each item in the list box begins with the date you are wanting to move to listbox2 //and the format is as per your example then the following code will do what you are after. //notice that I am not inserting or replacing anything just doing the job that needs to be done. DateTime t; for (int i = 0; i { t = DateTime.Parse(s[i].Substring(0 s[i].IndexOf( listBox2.Items.Addt.ToString(dd/MM/yy)); } //or this way DateTime t; for (int i = 0; i listBox1.Items.Add((t = DateTime.Parse(s[i].Substring(0 s[i].IndexOf( Unless of course using RegEx is essential for you to use just a couple of alternatives

Vulpes · Answer

I tested the Regex before posting and it was working OK picking out the single digit months just fine. However the rest of the code that you have is not quite right. Try it like this: string regExp1 = (? \d{12})/(? \d{1})/(? (\d{4}|\d{2})).*; string arr; for (int a = 0; a { arr = listBox1.Items[a].ToString(); if (Regex.IsMatch(arr regExp1)) { arr = arr.Insert(3 0); } arr = arr.Replace(  ); listBox2.Items.Add(arr); }

MIke Lumley · Answer

Hi Vulpes I Have a ListBox that has 100 or so items. some are like this: 05/7/11 John and some are like this 05/11/11 Sara But I all the single digit months to have a 0 in front so its like this: 05/07/11 Tena Can you see the difference in the date format I need them to say 07 not 7 because when I get to a month with 2 digits its goes wrong I can delete the tags at the end also the middle but need to set the date format so it Reads 05/07/11 that way I have a solid base to start deleting Using this only outputs the first item lots of times string regExp1 = (? \d{12})/(? \d{1})/(? ( \d{4}|\d{2 })).*; string arr; for (int a = 0; a { arr = listBox1.Items[a].ToString(); if (Regex.IsMatch(arr regExp1)) { arr = arr.Insert(3 0); arr = arr.Replace(  ); listBox2.Items.Add(arr); } listBox2.Items.Add(arr); } ps That Expresso is cool tool thank you for guidance there. Thanks Vulpes. Mike.

Vulpes · Answer

Try this: string regExp1 = (? \d{12})/(? \d{1})/(? (\d{4}|\d{2})).*; string arr; for (int a = 0; a { arr = arrStrUSA[a]; if (Regex.IsMatch(arrregExp1)) { arr = arr.Insert(3 0); } arr = arr.Replace(  ); listBox2.Items.Add(arr); } Notice that this just gets rid of the final tags after the name as it wasn't clear what you want to do with the tags before the name.