Middle (Function)

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Functions for managing strings

Middle

Presentation

Example

Middle function and UNICODE

Various

Operating mode in GO mode and at run time

See also

Middle (Function)

In french: Milieu

Extracts:

a sub-string from a given position in a string.
a section from a given position in a buffer.

In this version, no section can be extracted from a buffer.

Remark: The same feature can be obtained with the [[]] operator.

Versions 15 and later

This function is now available for Android applications.

New in version 15

This function is now available for Android applications.

Versions 17 and later

This function is now available for iPhone/iPad applications.

New in version 17

This function is now available for iPhone/iPad applications.

Versions 18 and later

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

New in version 18

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

Versions 21 and later

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

Example

// Extract characters
Middle("Eponine", 2, 3) // Returns "pon"
Middle("Eponine", 2) // Returns "ponine"
Middle("Eponine", 50) // Returns ""
Middle("Eponine", 2, 50) // Returns "ponine"
// Equivalent to
// MyString is string = Eponine
// MyString = MyString[[2,50]]

MyString is string = "Antananarivo - Madagascar"
Middle(MyString, 10, 7) // Returns "ivo - M"

// Extract the bytes
MyBuffer is Buffer = "Antananarivo - Madagascar"
Middle(MyBuffer, 10, 7) // Returns "ivo - M"

Syntax

Extracting a sub-string from a string Hide the details

<Result> = Middle(<Source string> , <Start position> [, <Length>])

<Result>: Character string

Part of <Source String>.
Empty string ("") if <Start Position> is greater than the length of <Source String>.
EOT if <Start Position> and/or <Length> are negative. A WLanguage error occurs (non-fatal error). To find out the error details, use ErrorInfo.

<Source string>: Character string

Character string containing the sub-string to extract. This string is not modified.

<Start position>: Integer

Position of first character to extract.
If <Start Position> is null, the extraction starts from the beginning of string.

<Length>: Optional integer

Number of characters to extract.
If this parameter is not specified or if it is greater than the number of characters found after <Start Position>, the string is returned from <Start Position>.

Extracting part of a buffer Hide the details

<Result> = Middle(<Source buffer> , <Start position> [, <Size>])

<Result>: Character string

Part of <Source Buffer>.
Empty string ("") if <Start Position> is greater than the size of <Source Buffer>.
EOT if <Start Position> and/or <Size> are negative. A WLanguage error occurs (non-fatal error). To find out the error details, use ErrorInfo.
Invalid buffer if <Source Buffer> contains a character string in UNICODE format.
Invalid buffer if <Source Buffer> contains a character string in ANSI format.

<Source buffer>: Buffer

Buffer containing the part to extract. This buffer is not modified.

<Start position>: Integer

Position of first byte to extract.
If <Start Position> is null, the extraction starts from the beginning of buffer.

<Size>: Optional integer

Number of bytes to extract.
If this parameter is not specified or if it is greater than the number of characters found after <Start Position>, the string is returned from <Start Position>.
In UNICODE, each character occupies two memory bytes. Therefore, the number of bytes is twice the number of characters.

Remarks

Middle function and UNICODE

If the string passed in parameter is in ANSI format, the result will be in ANSI format.

If the string passed in parameter is in UNICODE format, the result will be in UNICODE format.

The subscript of the first character in the string is set to 1.

In UNICODE, each character occupies two memory bytes. Therefore, the memory footprint of a UNICODE string is twice the number of characters actually found in the string.

Remark: If the result on an ANSI string is assigned to a UNICODE string (and conversely), the conversion will be implicitly performed.

See Managing the UNICODE format for more details.

Various

The same feature can be obtained with the [[]] operator.

Operating mode in GO mode and at run time

In GO mode (simulation on the development), when extracting part of a buffer (syntax 2), <Size> corresponds to the number of characters to extract (and not to the number of bytes).

For example, running the following code:

MyBuffer is Buffer = "WINDEV is tremendous"
Middle(MyBuffer, 12, 4)

in GO mode, returns "derful".
at run time, returns "is ".

The differences between GO mode (simulator) and real use are presented in Differences between GO mode and real use.

Component : wd250vm.dll