Like Operator (Visual Basic)
Compares a string against a pattern.
Like operator is currently not supported in .NET Core and .NET Standard projects.
result = string Like pattern
Boolean variable. The result is a
Boolean value indicating whether or not the
string satisfies the
String expression conforming to the pattern-matching conventions described in "Remarks."
If the value in
string satisfies the pattern contained in
True. If the string does not satisfy the pattern,
False. If both
pattern are empty strings, the result is
The behavior of the
Like operator depends on the Option Compare Statement. The default string comparison method for each source file is
Option Compare Binary.
Built-in pattern matching provides a versatile tool for string comparisons. The pattern-matching features allow you to match each character in
string against a specific character, a wildcard character, a character list, or a character range. The following table shows the characters allowed in
pattern and what they match.
||Any single character|
||Zero or more characters|
||Any single digit (0–9)|
||Any single character in
||Any single character not in
A group of one or more characters (
charlist) enclosed in brackets (
[ ]) can be used to match any single character in
string and can include almost any character code, including digits.
An exclamation point (
!) at the beginning of
charlist means that a match is made if any character except the characters in
charlist is found in
string. When used outside brackets, the exclamation point matches itself.
To match the special characters left bracket (
[), question mark (
?), number sign (
#), and asterisk (
*), enclose them in brackets. The right bracket (
]) cannot be used within a group to match itself, but it can be used outside a group as an individual character.
The character sequence
 is considered a zero-length string (
""). However, it cannot be part of a character list enclosed in brackets. If you want to check whether a position in
string contains one of a group of characters or no character at all, you can use
Like twice. For an example, see How to: Match a String against a Pattern.
By using a hyphen (
–) to separate the lower and upper bounds of the range,
charlist can specify a range of characters. For example,
[A–Z] results in a match if the corresponding character position in
string contains any character within the range
[!H–L] results in a match if the corresponding character position contains any character outside the range
When you specify a range of characters, they must appear in ascending sort order, that is, from lowest to highest. Thus,
[A–Z] is a valid pattern, but
[Z–A] is not.
Multiple Character Ranges
To specify multiple ranges for the same character position, put them within the same brackets without delimiters. For example,
[A–CX–Z] results in a match if the corresponding character position in
string contains any character within either the range
C or the range
Usage of the Hyphen
A hyphen (
–) can appear either at the beginning (after an exclamation point, if any) or at the end of
charlist to match itself. In any other location, the hyphen identifies a range of characters delimited by the characters on either side of the hyphen.
The meaning of a specified range depends on the character ordering at run time, as determined by
Option Compare and the locale setting of the system the code is running on. With
Option Compare Binary, the range
Option Compare Text,
e. The range does not match
ê because accented characters collate after unaccented characters in the sort order.
In some languages, there are alphabetic characters that represent two separate characters. For example, several languages use the character
æ to represent the characters
e when they appear together. The
Like operator recognizes that the single digraph character and the two individual characters are equivalent.
When a language that uses a digraph character is specified in the system locale settings, an occurrence of the single digraph character in either
string matches the equivalent two-character sequence in the other string. Similarly, a digraph character in
pattern enclosed in brackets (by itself, in a list, or in a range) matches the equivalent two-character sequence in
Like operator can be overloaded, which means that a class or structure can redefine its behavior when an operand has the type of that class or structure. If your code uses this operator on such a class or structure, be sure you understand its redefined behavior. For more information, see Operator Procedures.
This example uses the
Like operator to compare strings to various patterns. The results go into a
Boolean variable indicating whether each string satisfies the pattern.
Dim testCheck As Boolean ' The following statement returns True (does "F" satisfy "F"?) testCheck = "F" Like "F" ' The following statement returns False for Option Compare Binary ' and True for Option Compare Text (does "F" satisfy "f"?) testCheck = "F" Like "f" ' The following statement returns False (does "F" satisfy "FFF"?) testCheck = "F" Like "FFF" ' The following statement returns True (does "aBBBa" have an "a" at the ' beginning, an "a" at the end, and any number of characters in ' between?) testCheck = "aBBBa" Like "a*a" ' The following statement returns True (does "F" occur in the set of ' characters from "A" through "Z"?) testCheck = "F" Like "[A-Z]" ' The following statement returns False (does "F" NOT occur in the ' set of characters from "A" through "Z"?) testCheck = "F" Like "[!A-Z]" ' The following statement returns True (does "a2a" begin and end with ' an "a" and have any single-digit number in between?) testCheck = "a2a" Like "a#a" ' The following statement returns True (does "aM5b" begin with an "a", ' followed by any character from the set "L" through "P", followed ' by any single-digit number, and end with any character NOT in ' the character set "c" through "e"?) testCheck = "aM5b" Like "a[L-P]#[!c-e]" ' The following statement returns True (does "BAT123khg" begin with a ' "B", followed by any single character, followed by a "T", and end ' with zero or more characters of any type?) testCheck = "BAT123khg" Like "B?T*" ' The following statement returns False (does "CAT123khg"?) begin with ' a "B", followed by any single character, followed by a "T", and ' end with zero or more characters of any type?) testCheck = "CAT123khg" Like "B?T*"
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