String.Split Method (System) (original) (raw)

Source:

String.Manipulation.cs

Source:

String.Manipulation.cs

Source:

String.Manipulation.cs

Source:

String.Manipulation.cs

Splits a string into a maximum number of substrings based on specified delimiting strings and, optionally, options.

public:
 cli::array <System::String ^> ^ Split(cli::array <System::String ^> ^ separator, int count, StringSplitOptions options);

public string[] Split(string[] separator, int count, StringSplitOptions options);

public string[] Split(string[]? separator, int count, StringSplitOptions options);

[System.Runtime.InteropServices.ComVisible(false)]
public string[] Split(string[] separator, int count, StringSplitOptions options);

member this.Split : string[] * int * StringSplitOptions -> string[]

[<System.Runtime.InteropServices.ComVisible(false)>]
member this.Split : string[] * int * StringSplitOptions -> string[]

Public Function Split (separator As String(), count As Integer, options As StringSplitOptions) As String()

Parameters

separator

String[]

The strings that delimit the substrings in this string, an empty array that contains no delimiters, or null.

count

Int32

The maximum number of substrings to return.

options

StringSplitOptions

A bitwise combination of the enumeration values that specifies whether to trim substrings and include empty substrings.

Returns

An array whose elements contain the substrings in this string that are delimited by one or more strings in separator. For more information, see the Remarks section.

Attributes

Exceptions

Examples

The following example uses the StringSplitOptions enumeration to include or exclude substrings generated by the Split method.

// This example demonstrates the String.Split() methods that use
// the StringSplitOptions enumeration.

// Example 1: Split a string delimited by characters
Console.WriteLine("1) Split a string delimited by characters:\n");

string s1 = ",ONE,, TWO,, , THREE,,";
char[] charSeparators = new char[] { ',' };
string[] result;

Console.WriteLine($"The original string is: \"{s1}\".");
Console.WriteLine($"The delimiter character is: '{charSeparators[0]}'.\n");

// Split the string and return all elements
Console.WriteLine("1a) Return all elements:");
result = s1.Split(charSeparators, StringSplitOptions.None);
Show(result);

// Split the string and return all elements with whitespace trimmed
Console.WriteLine("1b) Return all elements with whitespace trimmed:");
result = s1.Split(charSeparators, StringSplitOptions.TrimEntries);
Show(result);

// Split the string and return all non-empty elements
Console.WriteLine("1c) Return all non-empty elements:");
result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string and return all non-whitespace elements with whitespace trimmed
Console.WriteLine("1d) Return all non-whitespace elements with whitespace trimmed:");
result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Split the string into only two elements, keeping the remainder in the last match
Console.WriteLine("1e) Split into only two elements:");
result = s1.Split(charSeparators, 2, StringSplitOptions.None);
Show(result);

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("1f) Split into only two elements with whitespace trimmed:");
result = s1.Split(charSeparators, 2, StringSplitOptions.TrimEntries);
Show(result);

// Split the string into only two non-empty elements, keeping the remainder in the last match
Console.WriteLine("1g) Split into only two non-empty elements:");
result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("1h) Split into only two non-whitespace elements with whitespace trimmed:");
result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Example 2: Split a string delimited by another string
Console.WriteLine("2) Split a string delimited by another string:\n");

string s2 = "[stop]" +
            "ONE[stop] [stop]" +
            "TWO  [stop][stop]  [stop]" +
            "THREE[stop][stop]  ";
string[] stringSeparators = new string[] { "[stop]" };

Console.WriteLine($"The original string is: \"{s2}\".");
Console.WriteLine($"The delimiter string is: \"{stringSeparators[0]}\".\n");

// Split the string and return all elements
Console.WriteLine("2a) Return all elements:");
result = s2.Split(stringSeparators, StringSplitOptions.None);
Show(result);

// Split the string and return all elements with whitespace trimmed
Console.WriteLine("2b) Return all elements with whitespace trimmed:");
result = s2.Split(stringSeparators, StringSplitOptions.TrimEntries);
Show(result);

// Split the string and return all non-empty elements
Console.WriteLine("2c) Return all non-empty elements:");
result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string and return all non-whitespace elements with whitespace trimmed
Console.WriteLine("2d) Return all non-whitespace elements with whitespace trimmed:");
result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Split the string into only two elements, keeping the remainder in the last match
Console.WriteLine("2e) Split into only two elements:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.None);
Show(result);

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("2f) Split into only two elements with whitespace trimmed:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.TrimEntries);
Show(result);

// Split the string into only two non-empty elements, keeping the remainder in the last match
Console.WriteLine("2g) Split into only two non-empty elements:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("2h) Split into only two non-whitespace elements with whitespace trimmed:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Display the array of separated strings using a local function
void Show(string[] entries)
{
    Console.WriteLine($"The return value contains these {entries.Length} elements:");
    foreach (string entry in entries)
    {
        Console.Write($"<{entry}>");
    }
    Console.Write("\n\n");
}

/*
This example produces the following results:

1) Split a string delimited by characters:

The original string is: ",ONE,, TWO,, , THREE,,".
The delimiter character is: ','.

1a) Return all elements:
The return value contains these 9 elements:
<><ONE><>< TWO><>< >< THREE><><>

1b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

1c) Return all non-empty elements:
The return value contains these 4 elements:
<ONE>< TWO>< >< THREE>

1d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

1e) Split into only two elements:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< TWO,, , THREE,,>

1h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO,, , THREE,,>

2) Split a string delimited by another string:

The original string is: "[stop]ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  ".
The delimiter string is: "[stop]".

2a) Return all elements:
The return value contains these 9 elements:
<><ONE>< ><TWO  ><><  ><THREE><><  >

2b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

2c) Return all non-empty elements:
The return value contains these 6 elements:
<ONE>< ><TWO  ><  ><THREE><  >

2d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

2e) Split into only two elements:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]>

2g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO  [stop][stop]  [stop]THREE[stop][stop]>

*/

// This example demonstrates the String.Split() methods that use
// the StringSplitOptions enumeration.

// Display the array of separated strings using a local function
let show  (entries: string[]) =
    printfn $"The return value contains these {entries.Length} elements:"
    for entry in entries do
        printf $"<{entry}>"
    printf "\n\n"

// Example 1: Split a string delimited by characters
printfn "1) Split a string delimited by characters:\n"

let s1 = ",ONE,, TWO,, , THREE,,"
let charSeparators = [| ',' |]

printfn $"The original string is: \"{s1}\"."
printfn $"The delimiter character is: '{charSeparators[0]}'.\n"

// Split the string and return all elements
printfn "1a) Return all elements:"
let result = s1.Split(charSeparators, StringSplitOptions.None)
show result

// Split the string and return all elements with whitespace trimmed
printfn "1b) Return all elements with whitespace trimmed:"
let result = s1.Split(charSeparators, StringSplitOptions.TrimEntries)
show result

// Split the string and return all non-empty elements
printfn "1c) Return all non-empty elements:"
let result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries)
show result

// Split the string and return all non-whitespace elements with whitespace trimmed
printfn "1d) Return all non-whitespace elements with whitespace trimmed:"
let result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries ||| StringSplitOptions.TrimEntries)
show result


// Split the string into only two elements, keeping the remainder in the last match
printfn "1e) Split into only two elements:"
let result = s1.Split(charSeparators, 2, StringSplitOptions.None)
show result

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
printfn "1f) Split into only two elements with whitespace trimmed:"
let result = s1.Split(charSeparators, 2, StringSplitOptions.TrimEntries)
show result

// Split the string into only two non-empty elements, keeping the remainder in the last match
printfn "1g) Split into only two non-empty elements:"
let result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries)
show result

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
printfn "1h) Split into only two non-whitespace elements with whitespace trimmed:"
let result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries ||| StringSplitOptions.TrimEntries)
show result


// Example 2: Split a string delimited by another string
printfn "2) Split a string delimited by another string:\n"

let s2 = "[stop]" +
            "ONE[stop] [stop]" +
            "TWO  [stop][stop]  [stop]" +
            "THREE[stop][stop]  "
let stringSeparators = [| "[stop]" |]

printfn $"The original string is: \"{s2}\"."
printfn $"The delimiter string is: \"{stringSeparators[0]}\".\n"

// Split the string and return all elements
printfn "2a) Return all elements:"
let result = s2.Split(stringSeparators, StringSplitOptions.None)
show result

// Split the string and return all elements with whitespace trimmed
printfn "2b) Return all elements with whitespace trimmed:"
let result = s2.Split(stringSeparators, StringSplitOptions.TrimEntries)
show result

// Split the string and return all non-empty elements
printfn "2c) Return all non-empty elements:"
let result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries)
show result

// Split the string and return all non-whitespace elements with whitespace trimmed
printfn "2d) Return all non-whitespace elements with whitespace trimmed:"
let result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries ||| StringSplitOptions.TrimEntries)
show result


// Split the string into only two elements, keeping the remainder in the last match
printfn "2e) Split into only two elements:"
let result = s2.Split(stringSeparators, 2, StringSplitOptions.None)
show result

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
printfn "2f) Split into only two elements with whitespace trimmed:"
let result = s2.Split(stringSeparators, 2, StringSplitOptions.TrimEntries)
show result

// Split the string into only two non-empty elements, keeping the remainder in the last match
printfn "2g) Split into only two non-empty elements:"
let result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries)
show result

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
printfn "2h) Split into only two non-whitespace elements with whitespace trimmed:"
let result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries ||| StringSplitOptions.TrimEntries)
show result

(*
This example produces the following results:

1) Split a string delimited by characters:

The original string is: ",ONE,, TWO,, , THREE,,".
The delimiter character is: ','.

1a) Return all elements:
The return value contains these 9 elements:
<><ONE><>< TWO><>< >< THREE><><>

1b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

1c) Return all non-empty elements:
The return value contains these 4 elements:
<ONE>< TWO>< >< THREE>

1d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

1e) Split into only two elements:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< TWO,, , THREE,,>

1h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO,, , THREE,,>

2) Split a string delimited by another string:

The original string is: "[stop]ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  ".
The delimiter string is: "[stop]".

2a) Return all elements:
The return value contains these 9 elements:
<><ONE>< ><TWO  ><><  ><THREE><><  >

2b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

2c) Return all non-empty elements:
The return value contains these 6 elements:
<ONE>< ><TWO  ><  ><THREE><  >

2d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

2e) Split into only two elements:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]>

2g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO  [stop][stop]  [stop]THREE[stop][stop]>

*)

Public Shared Sub StringSplitOptionsExamples()
    ' This example demonstrates the String.Split() methods that use
    ' the StringSplitOptions enumeration.

    ' Example 1: Split a string delimited by characters
    Console.WriteLine("1) Split a string delimited by characters:" & vbCrLf)

    Dim s1 As String = ",ONE,, TWO,, , THREE,,"
    Dim charSeparators() As Char = {","c}
    Dim result() As String

    Console.WriteLine("The original string is: ""{0}"".", s1)
    Console.WriteLine("The delimiter character is: '{0}'." & vbCrLf, charSeparators(0))

    ' Split the string and return all elements
    Console.WriteLine("1a) Return all elements:")
    result = s1.Split(charSeparators, StringSplitOptions.None)
    Show(result)

    ' Split the string and return all elements with whitespace trimmed
    Console.WriteLine("1b) Return all elements with whitespace trimmed:")
    result = s1.Split(charSeparators, StringSplitOptions.TrimEntries)
    Show(result)

    ' Split the string and return all non-empty elements
    Console.WriteLine("1c) Return all non-empty elements:")
    result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries)
    Show(result)

    ' Split the string and return all non-whitespace elements with whitespace trimmed
    Console.WriteLine("1d) Return all non-whitespace elements with whitespace trimmed:")
    result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries Or StringSplitOptions.TrimEntries)
    Show(result)


    ' Split the string into only two elements, keeping the remainder in the last match
    Console.WriteLine("1e) Split into only two elements:")
    result = s1.Split(charSeparators, 2, StringSplitOptions.None)
    Show(result)

    ' Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
    Console.WriteLine("1f) Split into only two elements with whitespace trimmed:")
    result = s1.Split(charSeparators, 2, StringSplitOptions.TrimEntries)
    Show(result)

    ' Split the string into only two non-empty elements, keeping the remainder in the last match
    Console.WriteLine("1g) Split into only two non-empty elements:")
    result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries)
    Show(result)

    ' Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
    Console.WriteLine("1h) Split into only two non-whitespace elements with whitespace trimmed:")
    result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries Or StringSplitOptions.TrimEntries)
    Show(result)


    ' Example 2: Split a string delimited by another string
    Console.WriteLine("2) Split a string delimited by another string:" & vbCrLf)

    Dim s2 As String = "[stop]" +
                "ONE[stop] [stop]" +
                "TWO  [stop][stop]  [stop]" +
                "THREE[stop][stop]  "
    Dim stringSeparators() As String = {"[stop]"}


    Console.WriteLine("The original string is: ""{0}"".", s2)
    Console.WriteLine("The delimiter string is: ""{0}""." & vbCrLf, stringSeparators(0))

    ' Split the string and return all elements
    Console.WriteLine("2a) Return all elements:")
    result = s2.Split(stringSeparators, StringSplitOptions.None)
    Show(result)

    ' Split the string and return all elements with whitespace trimmed
    Console.WriteLine("2b) Return all elements with whitespace trimmed:")
    result = s2.Split(stringSeparators, StringSplitOptions.TrimEntries)
    Show(result)

    ' Split the string and return all non-empty elements
    Console.WriteLine("2c) Return all non-empty elements:")
    result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries)
    Show(result)

    ' Split the string and return all non-whitespace elements with whitespace trimmed
    Console.WriteLine("2d) Return all non-whitespace elements with whitespace trimmed:")
    result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries Or StringSplitOptions.TrimEntries)
    Show(result)


    ' Split the string into only two elements, keeping the remainder in the last match
    Console.WriteLine("2e) Split into only two elements:")
    result = s2.Split(stringSeparators, 2, StringSplitOptions.None)
    Show(result)

    ' Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
    Console.WriteLine("2f) Split into only two elements with whitespace trimmed:")
    result = s2.Split(stringSeparators, 2, StringSplitOptions.TrimEntries)
    Show(result)

    ' Split the string into only two non-empty elements, keeping the remainder in the last match
    Console.WriteLine("2g) Split into only two non-empty elements:")
    result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries)
    Show(result)

    ' Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
    Console.WriteLine("2h) Split into only two non-whitespace elements with whitespace trimmed:")
    result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries Or StringSplitOptions.TrimEntries)
    Show(result)

End Sub

' Display the array of separated strings.
Public Shared Sub Show(ByVal entries() As String)
    Console.WriteLine("The return value contains these {0} elements:", entries.Length)
    Dim entry As String
    For Each entry In entries
        Console.Write("<{0}>", entry)
    Next entry
    Console.Write(vbCrLf & vbCrLf)

End Sub

'This example produces the following results:
'
' 1) Split a string delimited by characters:
'
' The original string is: ",ONE,, TWO,, , THREE,,".
' The delimiter character is: ','.
'
' 1a) Return all elements:
' The return value contains these 9 elements:
' <><ONE><>< TWO><>< >< THREE><><>
'
' 1b) Return all elements with whitespace trimmed:
' The return value contains these 9 elements:
' <><ONE><><TWO><><><THREE><><>
'
' 1c) Return all non-empty elements:
' The return value contains these 4 elements:
' <ONE>< TWO>< >< THREE>
'
' 1d) Return all non-whitespace elements with whitespace trimmed:
' The return value contains these 3 elements:
' <ONE><TWO><THREE>
'
' 1e) Split into only two elements:
' The return value contains these 2 elements:
' <><ONE,, TWO,, , THREE,,>
'
' 1f) Split into only two elements with whitespace trimmed:
' The return value contains these 2 elements:
' <><ONE,, TWO,, , THREE,,>
'
' 1g) Split into only two non-empty elements:
' The return value contains these 2 elements:
' <ONE>< TWO,, , THREE,,>
'
' 1h) Split into only two non-whitespace elements with whitespace trimmed:
' The return value contains these 2 elements:
' <ONE><TWO,, , THREE,,>
'
' 2) Split a string delimited by another string:
'
' The original string is: "[stop]ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  ".
' The delimiter string is: "[stop]".
'
' 2a) Return all elements:
' The return value contains these 9 elements:
' <><ONE>< ><TWO  ><><  ><THREE><><  >
'
' 2b) Return all elements with whitespace trimmed:
' The return value contains these 9 elements:
' <><ONE><><TWO><><><THREE><><>
'
' 2c) Return all non-empty elements:
' The return value contains these 6 elements:
' <ONE>< ><TWO  ><  ><THREE><  >
'
' 2d) Return all non-whitespace elements with whitespace trimmed:
' The return value contains these 3 elements:
' <ONE><TWO><THREE>
'
' 2e) Split into only two elements:
' The return value contains these 2 elements:
' <><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >
'
' 2f) Split into only two elements with whitespace trimmed:
' The return value contains these 2 elements:
' <><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]>
'
' 2g) Split into only two non-empty elements:
' The return value contains these 2 elements:
' <ONE>< [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >
'
' 2h) Split into only two non-whitespace elements with whitespace trimmed:
' The return value contains these 2 elements:
' <ONE><TWO  [stop][stop]  [stop]THREE[stop][stop]>
'

Remarks

Delimiter strings are not included in the elements of the returned array.

If this instance does not contain any of the strings in separator, or the count parameter is 1, the returned array consists of a single element that contains this instance.

If the separator parameter is null or contains no characters, white-space characters are assumed to be the delimiters. White-space characters are defined by the Unicode standard and the Char.IsWhiteSpace method returns true if they are passed to it.

To pass null for the string[] separator parameter, you must indicate the type of the null to disambiguate the call from some other overloads, such as Split(Char[], Int32, StringSplitOptions). The following example shows several ways to unambiguously identify this overload.

string phrase = "The quick  brown fox";

_ = phrase.Split(default(string[]), 3, StringSplitOptions.RemoveEmptyEntries);

_ = phrase.Split((string[]?)null, 3, StringSplitOptions.RemoveEmptyEntries);

_ = phrase.Split(null as string[], 3, StringSplitOptions.RemoveEmptyEntries);

let phrase = "The quick  brown fox"

phrase.Split(Unchecked.defaultof<string[]>, 3, StringSplitOptions.RemoveEmptyEntries) |> ignore

phrase.Split(null :> string[], 3, StringSplitOptions.RemoveEmptyEntries) |> ignore

phrase.Split((null: string[]), 3, StringSplitOptions.RemoveEmptyEntries) |> ignore

Dim phrase As String = "The quick brown fox"
Dim words() As String

words = phrase.Split(TryCast(Nothing, String()), 3,
                       StringSplitOptions.RemoveEmptyEntries)

words = phrase.Split(New String() {}, 3,
                     StringSplitOptions.RemoveEmptyEntries)

If the count parameter is zero, or the options parameter is RemoveEmptyEntries and the length of this instance is zero, an empty array is returned.

Each element of separator defines a separate delimiter that consists of one or more characters. If the options parameter is None, and two delimiters are adjacent or a delimiter is found at the beginning or end of this instance, the corresponding array element contains Empty.

If there are more than count substrings in this instance, the first count minus 1 substrings are returned in the first count minus 1 elements of the return value, and the remaining characters in this instance are returned in the last element of the return value.

If count is greater than the number of substrings, the available substrings are returned and no exception is thrown.

The separator array

If any of the elements in separator consists of multiple characters, the entire substring is considered a delimiter. For example, if one of the elements in separator is "10", attempting to split the string "This10is10a10string." returns this four-element array: { "This", "is", "a", "string." }.

Comparison details

The Split method extracts the substrings in this string that are delimited by one or more of the strings in the separator parameter, and returns those substrings as elements of an array.

The Split method looks for delimiters by performing comparisons using case-sensitive ordinal sort rules. For more information about word, string, and ordinal sorts, see the System.Globalization.CompareOptions enumeration.

The Split method ignores any element of separator whose value is null or the empty string ("").

To avoid ambiguous results when strings in separator have characters in common, the Split method proceeds from the beginning to the end of the value of the instance, and matches the first element in separator that is equal to a delimiter in the instance. The order in which substrings are encountered in the instance takes precedence over the order of elements in separator.

For example, consider an instance whose value is "abcdef". If the first element in separator was "ef" and the second element was "bcde", the result of the split operation would be "a" and "f". This is because the substring in the instance, "bcde", is encountered and matches an element in separator before the substring "f" is encountered.

However, if the first element of separator was "bcd" and the second element was "bc", the result of the split operation would be "a" and "ef". This is because "bcd" is the first delimiter in separator that matches a delimiter in the instance. If the order of the separators was reversed so the first element was "bc" and the second element was "bcd", the result would be "a" and "def".

Performance considerations

The Split methods allocate memory for the returned array object and a String object for each array element. If your application requires optimal performance or if managing memory allocation is critical in your application, consider using the IndexOf or IndexOfAny method, and optionally the Compare method, to locate a substring within a string.

If you are splitting a string at a separator character, use the IndexOf or IndexOfAny method to locate a separator character in the string. If you are splitting a string at a separator string, use the IndexOf or IndexOfAny method to locate the first character of the separator string. Then use the Compare method to determine whether the characters after that first character are equal to the remaining characters of the separator string.

In addition, if the same set of characters is used to split strings in multiple Split method calls, consider creating a single array and referencing it in each method call. This significantly reduces the additional overhead of each method call.

Notes to Callers

In .NET Framework 3.5 and earlier versions, if the Split(Char[]) method is passed a separator that is null or contains no characters, the method uses a slightly different set of white-space characters to split the string than the Trim(Char[]) method does to trim the string. Starting with .NET Framework 4, both methods use an identical set of Unicode white-space characters.

String.Split Method (System) (original) (raw)

Parameters

Returns

Exceptions

Examples

Remarks

The separator array

Comparison details

Performance considerations

Notes to Callers

Applies to