Having a bit of trouble with converting a comma separated text file to a generic list. I have a class (called "Customers") defined with the following attributes:
Name (string)
City (string)
Balance (double)
CardNumber (int)
The values will be stored in a text file in this format: Name,City, Balance, CarNumber e.g. John,Memphis,10,200789. There will be multiple lines of this. What I want to do is have each line be placed in a list item when the user clicks a button.
I've worked out I can break each line up using the .Split() method, but have no idea how to make the correct value go into the correct attribute of the list. (Please note: I know how to use get/set properties, and I am not allowed to use LINQ to solve the problem).
Any help appreciated, as I am only learning and have been working on this for a for while with no luck. Thanks
EDIT:
Sorry, it appears I'm not making myself clear. I know how to use .add.
If I have two lines in the text file:
A,B,1,2 and
C,D,3,4
What I don't know how to do is make the name "field" in the list item in position 0 equal "A", and the name "field" in the item in position 1 equal "C" and so on.
Sorry for the poor use of terminology, I'm only learning. Hope you understand what I'm asking (I'm sure it's really easy to do once you know)
The result of string.Split will give you an array of strings:
string[] lineValues = line.Split(',');
You can access values in an array by index:
string name = lineValues[0];
string city = lineValues[1];
You can convert strings to double or int using their respective Parse methods:
double balance = double.Parse(lineValues[2]);
int cardNumber = int.Parse(lineValues[3]);
You can instantiate the class and assign to it very simply:
Customer customerForCurrentLine = new Customer()
{
Name = name,
City = city,
Balance = balance,
CardNumber = cardNumber,
};
Simply loop over the lines, instantiate a Customer for that line, and add it to a variable you've created of the type List<Customer>
If you want your program to be bulletproof, you're going to have to do a lot of checking to skip over lines that don't have enough values, or that would fail to parse to the correct number type. For example, check lineValues.Length == 4 and use int.TryParse(...) and double.TryParse(...).
Read a file and split its text based on newline character. Then for total line count run a loop that will split based on comma and create a new object and insert values in its properties and add that object to a list.
This way
List<Customers> lst = new List<Customers>();
string[] str = System.IO.File.ReadAllText(#"C:\CutomersFile.txt")
.Split(new string[] { Environment.NewLine },
StringSplitOptions.None);
for (int i = 0; i < str.Length; i++)
{
string[] s = str[i].Split(',');
Customers c = new Customers();
c.Name = s[0];
c.City = s[1];
c.Balance = Convert.ToDouble(s[2]);
c.CardNumber = Convert.ToInt32(s[3]);
lst.Add(c);
}
BTW class name should be Customer and not Customers
Split() generates an array of strings in the order they appeared in the source string. Thus, if your name field is the first column in the CSV file, it will always be the first index in the array.
someCustomer.Name = splitResult[0];
And so on. You'll also need to investigate String.TryParse for your class's numerically typed properties.
Related
I am a beginner in programming. And now I'm facing a task where I can't get any further. Probably it is relatively easy to solve.
This is what I want to do: I read out a .txt file and there are several lines of content.
Example what is in the .txt file:
text1,text2,text3
text1,text2,
text1,text2,text3,text4
I'm now ready to find the right line and use it. Then I want to split the line and assign each text to its own string.
I can do this if I know that this line have 4 words. But what if I don't know how many words this line have.
For example if I want to assign 5 strings but there are only 4 arrays in the column I get an error.
My program currently looks like this:
string reader = "text1,text2,text3,text4";
string[] words = reader.Split(',');
string word1 = words[0].ToString();
string word2 = words[1].ToString();
string word3 = words[2].ToString();
string word4 = words[3].ToString();
textBox1.Text = word3;
My goal is to find out how many words are in the string. And then pass each word to a separate string.
Thank you in advance
To get the length of the Array, you can easily use .Length
In your example, you just write
int arraylength = words.Length;
I don't understand, why do you want to create a new String for every value of the string-array? You can just use them in the array.
In your example you always user .ToString(), this isn't necessary because you already have a string.
An array is just multiple variables (in your example strings) which are connected to another.
I doubt if you want separated local variables like word1, word2 etc. To see why, let's
bring the idea to the point of absurdity. Imagine, that we have a small narration with 1234
words only. Do we really want to create word1, word2, ..., word1234 local variables?
So, let's stick to a single words array only:
string[] words = reader.Split(',');
Now, you can easily get array Length (i.e. number of items):
textBoxCount.Text = $"We have {words.Length} words in total";
Or get N-th word (let N be one based) from the words array:
string wordN = array.Length >= N ? array[N - 1] : "SomeDefaultValue";
In your case (3d word) it can be
// either 3d word or an empty string (when we have just two less words)
textBox1.Text = array.Length >= 3 ? array[3 - 1] : "";
Technically, you can use Linq and query the reader string:
using System.Linq;
...
// 3d word or empty string
textBox1.Text = reader.Split(',').ElementAtOrDefault(3 - 1) ?? "";
But Linq seems to be overshot here.
Ok guys so I've got this issue that is driving me nuts, lets say that I've got a string like this "aaa,bbb,ccc,ddd,eee,fff,ggg" (with out the double quotes) and all that I want to get is a sub-string from it, something like "ddd,eee,fff,ggg".
I also have to say that there's a lot of information and not all the strings look the same so i kind off need something generic.
thank you!
One way using split with a limit;
string str = "aaa,bbb,ccc,ddd,eee,fff,ggg";
int skip = 3;
string result = str.Split(new[] { ',' }, skip + 1)[skip];
// = "ddd,eee,fff,ggg"
I would use stringToSplit.Split(',')
Update:
var startComma = 3;
var value = string.Join(",", stringToSplit.Split(',').Where((token, index) => index > startComma));
Not really sure if all things between the commas are 3 length. If they are I would use choice 2. If they are all different, choice 1. A third choice would be choice 2 but implement .IndexOf(",") several times.
Two choices:
string yourString="aaa,bbb,ccc,ddd,eee,fff,ggg";
string[] partsOfString=yourString.Split(','); //Gives you an array were partsOfString[0] is "aaa" and partsOfString[1] is "bbb"
string trimmed=partsOfString[3]+","+partsOfString[4]+","+partsOfString[5]+","+partsOfSting[6];
OR
//Prints "ddd,eee,fff,ggg"
string trimmed=yourString.Substring(12,14) //Gets the 12th character of your string and goes 14 more characters.
I am attempting to import a .CSV file into my database which is a table export from an image management system. This system allows end-users to take images and (sometimes) split them into multiple images. There is a column in this report that signifies the file name of the image that I am tracking. If items are split in the image management system, the file name receives an underscore ("_") on the report. The previous file name is not kept. The way the items can possibly exist on the CSV are shown below:
Report 1 # 8:00AM: ABC.PNG
Report 2 # 8:30AM: ABC_1.PNG
ABC_2.PNG
Report 3 # 9:00AM: ABC_1_1.PNG
ABC_1_2.PNG
ABC_2_1.PNG
ABC_2_2.PNG
Report 4 # 9:30AM ABC_1_1_1.PNG
ABC_1_1_2.PNG
ABC_1_2.PNG
ABC_2_1.PNG
ABC_2_2.PNG
I am importing each file name into its own record. When an item is split, I would like to identify the previous version and update the original record, then add the new split record into my database. The key to knowing if an item is split is locating an underscore ("_").
I am not sure what I should do to recreate previous child names, I have to test every previous iteration of the file name to see if it exists. My problem is interpreting the current state of the file name and rebuilding all previous possibilities. I do not need the original name, only the first possible split name up until the current name. The code below shows kind of what I am getting at, but I am not sure how to do this cleanly.
String[] splitName = theStringToSplit.Split('_');
for (int i = 1; i < splitName.Length - 1; i++)
{
//should concat everything between 0 and i, not just 0 and I
//not sure if this is the best way or what I should do
MessageBox.Show(splitName[0] + "_" + splitName[i] + ".PNG");
}
The thing you are looking for is part of string.
So string.Join() might help you joining an array to a delimited string:
It also contains a parameter start index and number of items to use.
string[] s = new string[] { "2", "a", "b" };
string joined = string.Join("_", s, 0 ,3);
// joined will be "2_a_b"
Maybe you are using the wrong tool for you problem. If you want to keep the last "_", you may want to use LastIndexOf() or even Regular Expressions. Anyways: You should not unnecessarily rip of names and re-glue them. If done, do it cultrue invariant and not culture specific (there might be different interpretations of "-" or the low letter of "I".
string fnwithExt = "Abc_12_23.png";
string fn = System.IO.Path.GetFileName(fnwithExt);
int indexOf = fn.LastIndexOf('_');
string part1 = fn.Substring(0, indexOf-1);
string part2 = fn.Substring(indexOf+1);
string part3 = System.IO.Path.GetExtension(fnwithExt);
string original = System.IO.Path.ChangeExtension(part1 + "_"+ part2, part3);
I asked a similar question before but am just asking it from a slightly different angle.
I have a list of codes and underneath each code I have a bunch of values that are taken from the fields Subject and GenSubject.
Problem is these values(especially the general subjects) contain various elements, seperated by ';'. How can I incorperate the split function within the dictionary as to split the various values as I run the query?
while (dbReader.Read())
{
string code = (string)dbReader["CODE"];
string subject = (string)dbReader["SUBJECT"];
string generalSublject = (string)dbReader["GenSubject"];
dict.Add(code, new List<string> { subject,generalSublject });
}
This is the result of which I want to split the values wherever they need splitting.
(I want to split the values before adding them to the dictionary)
Thank you
Just split the generalSublject string and create the list based on it, then insert the subject as the first item.
var list = new List<string>(generalSublject.Split(new string[] { ";" },
StringSplitOptions.None));
list.Insert(0, subject);
dict.Add(code, list);
I have a string which consists of different fields. So what I want to do is get the different text and assign each of them into a field.
ex: Hello Allan IBM
so what I want to do is:
put these three words in different strings like
string Greeting = "Hello"
string Name = "Allan"
string Company = "IBM"
//all of it happening in a loop.
string data = "Hello Allan IBM"
string s = data[i].ToString();
string[] words = s.Split(',');
foreach (string word in words) {
Console.WriteLine(word);
}
any suggestions?
thanks hope to hear from you soon
If I understand correctly you have a string with place-holders and you want to put different string in those place-holders:
var format="{0}, {1} {2}. How are you?";
//string Greeting = "Hello"
//string Name = "Allan"
//string Company = "IBM"
//all of it happening in a loop.
string data = ...; //I think you have an array of strings separated by ,
foreach( va s in data){
{
//string s = data[i];//.ToString(); - it is already a string array
string[] words = data[i].Split(',');
Console.WriteLine(format, words[0], words[1], words[2]);
}
To me it sound not like a problem that can be solved with a loop. The essential problem is that the loop can only work if you do exactly the same operation on the items within the loop. If your problem doesn't fit, you end up with a dozen of lines of code within the loop to handle special cases, what could have been written in a shorter way without a loop.
If there are only two or three strings you have to set (what should be the case if you have named variables), assign them from the indexes of the split string. An alternative would be using regular expressions to match some patterns to make it more robust, if one of the expected strings is missing.
Another possibility would be to set attributes on members or properties like:
[MyParseAttribute(/*position*/ /*regex*/)]
string Greeting {get;set;}
And use reflexion to populate them. Here you could create a loop on all properties having that attribute, as it sounds to me that you are eager to create a loop :-)