We Keep Coding

split string c# based on math operator

(Calculator program)count in one step with math basic order
if there is a string = "5+2*6/9"(which is user input) how to get number 2 and 6?
i've been trying with split but if there is no '+' it fail :(
here is my code atm
string[] a = kalimat.Split('*');
string[] a1 = a[0].Split('+');
string[] a2 = a1[a1.Count() - 1].Split('-');
string[] b1 = a[1].Split('+');
string[] b2 = b1[0].Split('-');
ang1 = a2[a2.Count() - 1];
ang2 = b2[0];
angka1 = Convert.ToDouble(ang1);
angka2 = Convert.ToDouble(ang2);
hasil = angka1 * angka2;
any idea guys?

If you're input expression is always in the form: "[some number]+[first value you want to return]*[second value you want to return]" then this should work for you:
var reg = new System.Text.RegularExpressions.Regex(#"\d\+(\d)\*(\d)");
var result = reg.Match("5+2*6/9");
var first = result.Groups[1];
var second = result.Groups[2];
You can of course tweak the regular expression search pattern to suit your needs.

Parsing arbitrary mathematical expression is not a trivial task. If this isn't a homework that require you to do the parsing by hand, I would suggest to find a library for doing the task, like NCalc for example.
You can install it from Nuget, and use the following simple code :
var kalimat = "5+2*6/9";
var hasil = new NCalc.Expression(kalimat).Evaluate();
Console.WriteLine(hasil);
Selamat mencoba :)

Regex.Split and string.Split not working as expected

I am attempting to split strings using '?' as the delimiter. My code reads data from a CSV file, and certain symbols (like fractions) are not recognized by C#, so I am trying to replace them with a relevant piece of data (bond coupon in this case). I have print statements in the following code (which is embedded in a loop with index variable i) to test the output:
string[] l = lines[i][1].Split('?');
//string[] l = Regex.Split(lines[i][1], #"\?");
System.Console.WriteLine("L IS " + l.Length.ToString() + " LONG");
for (int j = 0; j < l.Length; j++)
System.Console.WriteLine("L["+ j.ToString() + "] IS " + l[j]);
if (l.Length > 1)
{
double cpn = Convert.ToDouble(lines[i][12]);
string couponFrac = (cpn - Math.Floor(cpn)).ToString().Remove(0,1);
lines[i][1] = l[0].Remove(l[0].Length-1) + couponFrac + l[1]; // Recombine, replacing '?' with CPN
}
The issue is that both split methods (string.Split() and Regex.Split() ) produce inconsistent results with some of the string elements in lines splitting correctly and the others not splitting at all (and thus the question mark is still in the string).
Any thoughts? I've looked at similar posts on split methods and they haven't been too helpful.

I had no problem using String.Split. Could you post your input and output?
If at all you could probably use String.Replace to replace your desired '?' with a character that does not occur in the string and then use String.Split on that character to split the resultant string for the same effect. (just a try)

I didn't have any trouble parsing the following.
var qsv = "now?is?the?time";
var keywords = qsv.Split('?');
keywords.Dump();
screenshot of code and output...
UPDATE:
There doesn't appear to be any problem with Split. There is a problem somewhere else because in this small scale test it works just fine. I would suggest you use LinqPad to test out these kinds of scenarios small scale.
var qsv = "TII 0 ? 04/15/15";
var keywords = qsv.Split('?');
keywords.Dump();
qsv = "TII 0 ? 01/15/22";
keywords = qsv.Split('?');
keywords.Dump();
New updated output:

Getting substring between two separators in an arbitrary position

I have following string:
string source = "Test/Company/Business/Department/Logs.tvs/v1";
The / character is the separator between various elements in the string. I need to get the last two elements of the string. I have following code for this purpose. This works fine. Is there any faster/simpler code for this?
CODE
static void Main()
{
string component = String.Empty;
string version = String.Empty;
string source = "Test/Company/Business/Department/Logs.tvs/v1";
if (!String.IsNullOrEmpty(source))
{
String[] partsOfSource = source.Split('/');
if (partsOfSource != null)
{
if (partsOfSource.Length > 2)
{
component = partsOfSource[partsOfSource.Length - 2];
}
if (partsOfSource.Length > 1)
{
version = partsOfSource[partsOfSource.Length - 1];
}
}
}
Console.WriteLine(component);
Console.WriteLine(version);
Console.Read();
}

Why no regular expression? This one is fairly easy:
.*/(?<component>.*)/(?<version>.*)$
You can even label your groups so for your match all you need to do is:
component = myMatch.Groups["component"];
version = myMatch.Groups["version"];

The following should be faster, as it only scans as much of the string as it needs to to find two / and it doesn't bother splitting up the whole string:
string component = "";
string version = "";
string source = "Test/Company/Business/Department/Logs.tvs/v1";
int last = source.LastIndexOf('/');
if (last != -1)
{
int penultimate = source.LastIndexOf('/', last - 1);
version = source.Substring(last + 1);
component = source.Substring(penultimate + 1, last - penultimate - 1);
}
That said, as with all performance questions: profile! Try the two side-by-side with a big list of real-life inputs and see which is fastest.
(Also, this will leave empty strings rather than throw an exception if there is no slash in the input... but throw if source is null, lazy me.)

Your approach is the most suitable one given that your are looking for substrings at a particular index. A LINQ expression to do the same in this case will likely not improve the code or its readability.
For reference, there is some great information from Microsoft here on working with strings and LINQ. In particular see the article here which covers some examples with both LINQ and RegEx.
EDIT: +1 For Matt's named group within RegEx approach... that's the nicest solution I've seen.

Your code mostly looks fine. A couple of points to note:
String.Split() will never return null, so you don't need the null check on it.
If the source string has fewer than two / characters, how would you deal with that? (The Original Post was updated to address this)
Do you really want to just output empty strings if your source string is null or empty (or invalid)? If you have specific expectations about the nature of the input, you may want to consider failing fast when those expectations are not met.

You could try something like this but I doubt it would be much faster. You could do some meassurements with System.Diagnostics.StopWatch to see if you feel the need.
string source = "Test/Company/Business/Department/Logs.tvs/v1";
int index1 = source.LastIndexOf('/');
string last = source.Substring(index1 + 1);
string substring = source.Substring(0, index1);
int index2 = substring.LastIndexOf('/');
string secondLast = substring.Substring(index2 + 1);

I would try
string source = "Test/Company/Business/Department/Logs.tvs/v1";
var components = source.Split('/').Reverse().Take(2);
String last = string.Empty;
var enumerable = components as string[] ?? components.ToArray();
if (enumerable.Count() == 2)
last = enumerable.FirstOrDefault();
var secondLast = enumerable.LastOrDefault();
Hope this will help

you can retrieve the last two words using the process as below:
string source = "Test/Company/Business/Department/Logs.tvs/v1";
String[] partsOfSource = source.Split('/');
if(partsOfSourch.length>2)
for(int i=partsOfSourch.length-2;i<=partsOfSource.length-1;i++)
console.writeline(partsOfSource[i]);

Extracting data from plain text string

I am trying to process a report from a system which gives me the following code
000=[GEN] OK {Q=1 M=1 B=002 I=3e5e65656-e5dd-45678-b785-a05656569e}
I need to extract the values between the curly brackets {} and save them in to variables. I assume I will need to do this using regex or similar? I've really no idea where to start!! I'm using c# asp.net 4.
I need the following variables
param1 = 000
param2 = GEN
param3 = OK
param4 = 1 //Q
param5 = 1 //M
param6 = 002 //B
param7 = 3e5e65656-e5dd-45678-b785-a05656569e //I
I will name the params based on what they actually mean. Can anyone please help me here? I have tried to split based on spaces, but I get the other garbage with it!
Thanks for any pointers/help!

If the format is pretty constant, you can use .NET string processing methods to pull out the values, something along the lines of
string line =
"000=[GEN] OK {Q=1 M=1 B=002 I=3e5e65656-e5dd-45678-b785-a05656569e}";
int start = line.IndexOf('{');
int end = line.IndexOf('}');
string variablePart = line.Substring(start + 1, end - start);
string[] variables = variablePart.Split(' ');
foreach (string variable in variables)
{
string[] parts = variable.Split('=');
// parts[0] holds the variable name, parts[1] holds the value
}
Wrote this off the top of my head, so there may be an off-by-one error somewhere. Also, it would be advisable to add error checking e.g. to make sure the input string has both a { and a }.

I would suggest a regular expression for this type of work.
var objRegex = new System.Text.RegularExpressions.Regex(#"^(\d+)=\[([A-Z]+)\] ([A-Z]+) \{Q=(\d+) M=(\d+) B=(\d+) I=([a-z0-9\-]+)\}$");
var objMatch = objRegex.Match("000=[GEN] OK {Q=1 M=1 B=002 I=3e5e65656-e5dd-45678-b785-a05656569e}");
if (objMatch.Success)
{
Console.WriteLine(objMatch.Groups[1].ToString());
Console.WriteLine(objMatch.Groups[2].ToString());
Console.WriteLine(objMatch.Groups[3].ToString());
Console.WriteLine(objMatch.Groups[4].ToString());
Console.WriteLine(objMatch.Groups[5].ToString());
Console.WriteLine(objMatch.Groups[6].ToString());
Console.WriteLine(objMatch.Groups[7].ToString());
}
I've just tested this out and it works well for me.

Use a regular expression.
Quick and dirty attempt:
(?<ID1>[0-9]*)=\[(?<GEN>[a-zA-Z]*)\] OK {Q=(?<Q>[0-9]*) M=(?<M>[0-9]*) B=(?<B>[0-9]*) I=(?<I>[a-zA-Z0-9\-]*)}
This will generate named groups called ID1, GEN, Q, M, B and I.
Check out the MSDN docs for details on using Regular Expressions in C#.
You can use Regex Hero for quick C# regex testing.

You can use String.Split
string[] parts = s.Split(new string[] {"=[", "] ", " {Q=", " M=", " B=", " I=", "}"},
StringSplitOptions.None);

This solution breaks up your report code into segments and stores the desired values into an array.
The regular expression matches one report code segment at a time and stores the appropriate values in the "Parsed Report Code Array".
As your example implied, the first two code segments are treated differently than the ones after that. I made the assumption that it is always the first two segments that are processed differently.
private static string[] ParseReportCode(string reportCode) {
const int FIRST_VALUE_ONLY_SEGMENT = 3;
const int GRP_SEGMENT_NAME = 1;
const int GRP_SEGMENT_VALUE = 2;
Regex reportCodeSegmentPattern = new Regex(#"\s*([^\}\{=\s]+)(?:=\[?([^\s\]\}]+)\]?)?");
Match matchReportCodeSegment = reportCodeSegmentPattern.Match(reportCode);
List<string> parsedCodeSegmentElements = new List<string>();
int segmentCount = 0;
while (matchReportCodeSegment.Success) {
if (++segmentCount < FIRST_VALUE_ONLY_SEGMENT) {
string segmentName = matchReportCodeSegment.Groups[GRP_SEGMENT_NAME].Value;
parsedCodeSegmentElements.Add(segmentName);
}
string segmentValue = matchReportCodeSegment.Groups[GRP_SEGMENT_VALUE].Value;
if (segmentValue.Length > 0) parsedCodeSegmentElements.Add(segmentValue);
matchReportCodeSegment = matchReportCodeSegment.NextMatch();
}
return parsedCodeSegmentElements.ToArray();
}

reading certain digits from binary data

I have one python script which i am trying to convert and stuck in one place and unable to proceed. Please check where ever i have mentioned "Stuck here" in below code. any help would be appreciated
Original Python script:
import hashlib
meid = raw_input("Enter an MEID: ").upper()
s = hashlib.sha1(meid.decode('hex'))
#decode the hex MEID (convert it to binary!)
pesn = "80" + s.hexdigest()[-6:].upper()
#put the last 6 digits of the hash after 80
print "pESN: " + pesn
My C# conversion:
UInt64 EsnDec = 2161133276;
string EsnHex=string.Format("{0:x}", EsnDec);
string m = Convert.ToString(Convert.ToUInt32(EsnHex, 16), 2);
/*---------------------------------------------
Stuck here. Now m got complete binary data
and i need to take last 6 digits as per python
script and prefix "80".
---------------------------------------------*/
Console.WriteLine(m);
Console.Read();

Use String.Substring:
// last 6 characters
string lastsix = m.Substring(m.Length - 6);
Console.WriteLine("80{0}", lastsix);

How about something like this:
static void Main(string[] args)
{
UInt64 EsnDec = 2161133276;
Console.WriteLine(EsnDec);
//Convert to String
string Esn = EsnDec.ToString();
Esn = "80" + Esn.Substring(Esn.Length - 6);
//Convert back to UInt64
EsnDec = Convert.ToUInt64(Esn);
Console.WriteLine(EsnDec);
Console.ReadKey();
}