Export (0) Print
Expand All

String.Split Method (String[], StringSplitOptions)

Returns a string array that contains the substrings in this string that are delimited by elements of a specified string array. A parameter specifies whether to return empty array elements.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

[ComVisibleAttribute(false)] 
public string[] Split (
	string[] separator,
	StringSplitOptions options
)
/** @attribute ComVisibleAttribute(false) */ 
public String[] Split (
	String[] separator, 
	StringSplitOptions options
)
ComVisibleAttribute(false) 
public function Split (
	separator : String[], 
	options : StringSplitOptions
) : String[]
Not applicable.

Parameters

separator

An array of strings that delimit the substrings in this string, an empty array that contains no delimiters, or a null reference (Nothing in Visual Basic).

options

Specify RemoveEmptyEntries to omit empty array elements from the array returned, or None to include empty array elements in the array returned.

Return Value

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.

Exception typeCondition

ArgumentException

options is not one of the StringSplitOptions values.

Return Value Details

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

If this instance does not contain any of the strings in separator, the returned array consists of a single element that contains this instance. If the separator parameter is a null reference (Nothing in Visual Basic) or contains no characters, white-space characters are assumed to be the delimiters. For a list of the characters that the Split method interprets as white space, see the table in the Remarks section of the String.Split(Char[]) method. (Note that this list is slightly different from the list of white-space characters recognized by the Trim method.)

If 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 character. 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.

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 a null reference (Nothing in Visual Basic) or the empty string ("").

To avoid ambiguous results when strings in separator have characters in common, the Split operation 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.

The following example illustrates the difference in the arrays returned by calling a string's String.Split(String[],StringSplitOptions) method with its options parameter equal to StringSplitOptions.None and StringSplitOptions.RemoveEmptyEntries.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

Community Additions

ADD
Show:
© 2014 Microsoft