I have a setting stored in database which has a value .jpg|.gif|.png . I want to display it on frontend as ".jpg",".gif" and ".png" in a single string. for example
Allowed formats are ".jpg",".gif" and ".png"
I was able to seperate it using
string fileTypes = String.Join(",", supportedFileTypes.Split('|'))
How to specify and clause before the last string. It has to be dynamic. For example if we have .jpg|.gif in database, it should be
Allowed formats are ".jpg" and ".gif".
public String formatAllowed(String allowedFormats)
{
String[] formats = allowedFormats.Split('|');
if (formats.Length == 1)
return formats[0];
StringBuilder sb = new StringBuilder(formats[0]);
for (int i = 1; i < formats.Length - 1; i++)
{
sb.AppendFormat(",\"{0}\"", formats[i]);
}
sb.AppendFormat(" and \"{0}\"", formats[formats.Length - 1]);
return sb.ToString();
}
sb.AppendFormat(",\"{0}\"", formats[i]);, which would use the String.Format style, and also wrap the formats in quotes as per the example.If you want in a single statement, we can do like this
return allowedFormats.IndexOf("|")>=0? string.Format("Allowed formats are {0}", allowedFormats.Insert(allowedFormats.LastIndexOf("|"), "and").Replace("and|", "and").Replace("|", ",")): allowedFormats;
String[] formats = ucBrandLogoFileUploadControl.Split('|');
String output = "Allowed formats are ";
for (int i = 0; i < formats.Length; i++)
{
if (i > 0)
{
if (i < formats.Length - 1) { output += ", "; }
else { output += " and "; }
}
output += "\"" + formats[i] + "\"";
}
I wouldn't be happy with the existing answers because they don't handle the "Allowed formats" prefix, which ought to vary also:
public static string FormatAllowed(string allowedFormats)
{
var formats = allowedFormats.Split(new[] {'|'},
StringSplitOptions.RemoveEmptyEntries);
return formats.Length == 0 ? "No formats allowed" :
formats.Length == 1 ? "Allowed format is \"" + formats[0] + "\"" :
string.Join("",
formats.Select(
(format, index) =>
(index == 0 ? "Allowed formats are " :
(index == formats.Length - 1 ? " and " : ", ")) +
"\"" + format + "\"")
.ToArray());
}
Test it like this:
static void Check(string formats, string expected)
{
var result = FormatAllowed(formats);
Console.WriteLine(result);
Debug.Assert(result == expected);
}
static void Main(string[] args)
{
Check("", "No formats allowed");
Check(".jpg", "Allowed format is \".jpg\"");
Check(".jpg|.png", "Allowed formats are \".jpg\" and \".png\"");
Check(".jpg|.gif|.png", "Allowed formats are \".jpg\", \".gif\" and \".png\"");
Check(".jpg|.gif|.png|.txt", "Allowed formats are \".jpg\", \".gif\", \".png\" and \".txt\"");
}
let's try sth like this
string result = "Allowed formats are ";
string[] tmp = ucBrandLogoFileUploadControl.SupportedFileTypes.Split('|');
if (tmp.Length == 1)
result += tmp[0];
else
{
string[] tmp2 = new string[tmp.Length-1];
Array.Copy(tmp, tmp2, tmp.Length-1);
result += String.Join(",",tmp2) + " and " + tmp[tmp.Length-1];
}
public static void Main()
{
Console.Out.WriteLine(Format("")); // no entries
Console.Out.WriteLine(Format(".jpg")); // one entry
Console.Out.WriteLine(Format(".jpg|.gif")); // two entries
Console.Out.WriteLine(Format(".jpg|.gif|.png")); // three entries
Console.In.ReadLine();
}
private static string Format(string extensionsText)
{
string[] extensions = extensionsText.Split('|');
if (extensions[0] == string.Empty) return "No formats are allowed";
if (extensions.Length == 1) return string.Format("Allowed format is \"{0}\".", extensions[0]);
var message = new StringBuilder("Allowed formats are ");
// first entry
message.Append('"').Append(extensions[0]).Append('"');
// middle entries
for (int index = 1; index < extensions.Length - 1; index += 1)
{
message.Append(", ");
message.Append('"').Append(extensions[index]).Append('"');
}
// last entry
message.Append(" and ");
message.Append('"').Append(extensions[extensions.Length - 1]).Append('"');
message.Append('.');
return message.ToString();
}
Outputs:
No formats are allowed Allowed format is ".jpg". Allowed formats are ".jpg" and ".gif". Allowed formats are ".jpg", ".gif" and ".png".
string[] fileTypes = supportedFileTypes.Split('|');
switch (fileTypes.Length)
{
case 0 : return "No format allowed";
case 1 : return String.Format("Allowed format is \"{0}\".", fileTypes[0]);
case 2 : return String.Format("Allowed formats are \"{0}\" and \"{1}\".", fileTypes[0], fileTypes[1]);
default :
string temp = "";
for (int i = 0; i < fileTypes.Length - 2; i++)
{
temp += String.Format(\"{0}\, ", fileTypes[i]);
}
return String.Format("Allowed formats are {0} \"{1}\" and \"{2}\".", temp, fileTypes[fileTypes.Length - 2], fileTypes[fileTypes.Length - 1]);
}
Pretty simple using linq :
public static string SupportedFilesToDisplayString(string supportedFileTypes)
{
if (supportedFileTypes == null)
{
throw new ArgumentNullException("supportedFileTypes");
}
var fileTypes = supportedFileTypes.Split('|')
.Select(s => string.Format("\"{0}\"", s));
var lastFileType = fileTypes.Skip(fileTypes.Count() - 1).SingleOrDefault();
var otherFileTypes = fileTypes.Take(fileTypes.Count() - 1);
if (otherFileTypes.Any())
{
var otherString = String.Join(", ", otherFileTypes.ToArray());
return string.Format("{0} and {1}", otherString, lastFileType);
}
else
{
return lastFileType;
}
}
Small test in Snippet compiler :
public static void RunSnippet()
{
WL(SupportedFilesToDisplayString(".jpg|.gif|.png"));
WL(SupportedFilesToDisplayString(".jpg|.png"));
WL(SupportedFilesToDisplayString(".png"));
WL(SupportedFilesToDisplayString(""));
WL(SupportedFilesToDisplayString(null));
}
Display :
".jpg", ".gif" and ".png"
".jpg", ".gif" and ".png"
".jpg" and ".png"
".png"
""
---
The following error occurred while executing the snippet:
System.ArgumentNullException: Value cannot be null.
Parameter name: supportedFileTypes
at MyClass.SupportedFilesToDisplayString(String supportedFileTypes)
at MyClass.RunSnippet()
at MyClass.Main()
---
string.Format("Allowed formats are \"{0}\"",
supportedFileTypes.Insert(supportedFileTypes.LastIndexOf("|"), "|")
.Replace("||", "\" and \"")
.Replace("|", "\",\""))
