Muokkaa

Jaa

about_Split

  • Artikkeli

Short description

Explains how to use the Split operator to split one or more strings into substrings.

Long description

The Split operator splits one or more strings into substrings. You can change the following elements of the Split operation:

  • Delimiter. The default is whitespace, but you can specify characters, strings, patterns, or script blocks that specify the delimiter. The Split operator in PowerShell uses a regular expression in the delimiter, rather than a simple character.
  • Maximum number of substrings. The default is to return all substrings. If you specify a number less than the number of substrings, the remaining substrings are concatenated in the last substring.
  • Options that specify the conditions under which the delimiter is matched, such as SimpleMatch and Multiline.

Syntax

The following diagram shows the syntax for the -split operator.

The parameter names do not appear in the command. Include only the parameter values. The values must appear in the order specified in the syntax diagram.

-Split <String>
-Split (<String[]>)
<String> -Split <Delimiter>[,<Max-substrings>[,"<Options>"]]
<String> -Split {<ScriptBlock>} [,<Max-substrings>]

You can substitute -iSplit or -cSplit for -split in any binary Split statement (a Split statement that includes a delimiter or script block). The -iSplit and -split operators are case-insensitive. The -cSplit operator is case-sensitive, meaning that case is considered when the delimiter rules are applied.

Parameters

<String> or <String[]>

Specifies one or more strings to be split. If you submit multiple strings, all the strings are split using the same delimiter rules.

Example:

-split "red yellow blue green"
red
yellow
blue
green

<Delimiter>

The characters that identify the end of a substring. The default delimiter is whitespace, including spaces and non-printable characters, such as newline (`n) and tab (`t). When the strings are split, the delimiter is omitted from all the substrings. Example:

"Lastname:FirstName:Address" -split ":"
Lastname
FirstName
Address

By default, the delimiter is omitted from the results. To preserve all or part of the delimiter, enclose in parentheses the part that you want to preserve. If the <Max-substrings> parameter is added, this takes precedence when your command splits up the collection. If you opt to include a delimiter as part of the output, the command returns the delimiter as part of the output; however, splitting the string to return the delimiter as part of output does not count as a split.

Examples:

"Lastname:FirstName:Address" -split "(:)"
Lastname
:
FirstName
:
Address

"Lastname/:/FirstName/:/Address" -split "/(:)/"
Lastname
:
FirstName
:
Address

<Max-substrings>

Specifies the maximum number of substrings returned by the split operation. The default is all substrings split by the delimiter. If there are more substrings, they are concatenated to the final substring. If there are fewer substrings, all substrings are returned. A value of 0 returns all the substrings.

Example:

$c = "Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune"
$c -split ",", 5

Mercury
Venus
Earth
Mars
Jupiter,Saturn,Uranus,Neptune

If you submit more than one string (an array of strings) to the -split operator, the Max-substrings limit is applied to each string separately.

$c = 'a,b,c','1,2,3,4,5'
$c -split ',', 3

a
b
c
1
2
3,4,5

<Max-substrings> does not specify the maximum number of objects that are returned. In the following example, <Max-substrings> is set to 3. This results in three substring values, but a total of five strings in the resulting output. The delimiter is included after the splits until the maximum of three substrings is reached. Additional delimiters in the final substring become part of the substring.

'Chocolate-Vanilla-Strawberry-Blueberry' -split '(-)', 3

Chocolate
-
Vanilla
-
Strawberry-Blueberry

Negative values are ignored.

<ScriptBlock>

An expression that specifies rules for applying the delimiter. The expression must evaluate to $true or $false. Enclose the script block in braces.

Example:

$c = "Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune"
$c -split {$_ -eq "e" -or $_ -eq "p"}

M
rcury,V
nus,
arth,Mars,Ju
it
r,Saturn,Uranus,N

tun

<Options>

Enclose the option name in quotation marks. Options are valid only when the <Max-substrings> parameter is used in the statement.

The syntax for the Options parameter is:

"SimpleMatch [,IgnoreCase]"

"[RegexMatch] [,IgnoreCase] [,CultureInvariant]
[,IgnorePatternWhitespace] [,ExplicitCapture]
[,Singleline | ,Multiline]"

The SimpleMatch options are:

  • SimpleMatch: Use simple string comparison when evaluating the delimiter. Cannot be used with RegexMatch.
  • IgnoreCase: Forces case-insensitive matching, even if the -cSplit operator is specified.

The RegexMatch options are:

  • RegexMatch: Use regular expression matching to evaluate the delimiter. This is the default behavior. Cannot be used with SimpleMatch.
  • IgnoreCase: Forces case-insensitive matching, even if the -cSplit operator is specified.
  • CultureInvariant: Ignores cultural differences in language when evaluating the delimiter. Valid only with RegexMatch.
  • IgnorePatternWhitespace: Ignores unescaped whitespace and comments marked with the number sign (#). Valid only with RegexMatch.
  • Multiline: Multiline mode forces ^ and $ to match the beginning end of every line instead of the beginning and end of the input string.
  • Singleline: Singleline mode treats the input string as a SingleLine. It forces the . character to match every character (including newlines), instead of matching every character EXCEPT the newline \n.
  • ExplicitCapture: Ignores non-named match groups so that only explicit capture groups are returned in the result list. Valid only with RegexMatch.

Note

SingleLine is the default behavior. Singleline and Multiline cannot be used together with the options parameter. This was resolved in PowerShell 6.0. The work around is by using Mode-Modifiers in your regular expression. You can read more about mode modifiers in Regular Expression Options

UNARY and BINARY SPLIT OPERATORS

The unary split operator (-split <string>) has higher precedence than a comma. As a result, if you submit a comma-separated list of strings to the unary split operator, only the first string (before the first comma) is split.

Use one of the following patterns to split more than one string:

  • Use the binary split operator (<string[]> -split <delimiter>)
  • Enclose all the strings in parentheses
  • Store the strings in a variable then submit the variable to the split operator

Consider the following example:

PS> -split "1 2", "a b"
1
2
a b

PS> "1 2", "a b" -split " "
1
2
a
b

PS> -split ("1 2", "a b")
1
2
a
b

PS> $a = "1 2", "a b"
PS> -split $a
1
2
a
b

Examples

The following statement splits the string at whitespace.

-split "Windows PowerShell 2.0`nWindows PowerShell with remoting"


Windows
PowerShell
2.0
Windows
PowerShell
with
remoting

The following statement splits the string at any comma.

"Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune" -split ','

Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune

The following statement splits the string at the pattern "er".

"Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune" -split 'er'

M
cury,Venus,Earth,Mars,Jupit
,Saturn,Uranus,Neptune

The following statement performs a case-sensitive split at the letter "N".

"Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune" -cSplit 'N'

Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,
eptune

The following statement splits the string at "e" and "t".

"Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune" -split '[et]'

M
rcury,V
nus,
ar
h,Mars,Jupi

r,Sa
urn,Uranus,N
p
un

The following statement splits the string at "e" and "r", but limits the resulting substrings to six substrings.

"Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune" -split '[er]', 6

M

cu
y,V
nus,
arth,Mars,Jupiter,Saturn,Uranus,Neptune

The following statement splits a string into three substrings.

"a,b,c,d,e,f,g,h" -split ",", 3

a
b
c,d,e,f,g,h

The following statement splits two strings into three substrings. (The limit is applied to each string independently.)

"a,b,c,d", "e,f,g,h" -split ",", 3

a
b
c,d
e
f
g,h

The following statement splits each line in the here-string at the first digit. It uses the Multiline option to recognize the beginning of each line and string.

The 0 represents the "return all" value of the Max-substrings parameter. You can use options, such as Multiline, only when the Max-substrings value is specified.

$a = @'
1The first line.
2The second line.
3The third of three lines.
'@
$a -split "^\d", 0, "multiline"


The first line.

The second line.

The third of three lines.

The following statement uses the backslash character to escape the dot (.) delimiter.

With the default, RegexMatch, the dot enclosed in quotation marks (".") is interpreted to match any character except for a newline character. As a result, the Split statement returns a blank line for every character except newline.

"This.is.a.test" -split "\."

This
is
a
test

The following statement uses the SimpleMatch option to direct the -split operator to interpret the dot (.) delimiter literally.

The 0 represents the "return all" value of the Max-substrings parameter. You can use options, such as SimpleMatch, only when the Max-substrings value is specified.

"This.is.a.test" -split ".", 0, "simplematch"

This
is
a
test

The following statement splits the string at one of two delimiters, depending on the value of a variable.

$i = 1
$c = "LastName, FirstName; Address, City, State, Zip"
$c -split $(if ($i -lt 1) {","} else {";"})

LastName, FirstName
 Address, City, State, Zip

See also