Left (Function)

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Functions for managing strings

Left

Presentation

Example

Left function and UNICODE

Operating mode in GO mode and at run time

See also

Left (Function)

In french: Gauche

Extracts the left part (which means the first characters) from a character string or from a buffer.

In this version, the left part of a buffer cannot be extracted.

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 16 and later

This function is now available for Windows Phone applications.

New in version 16

This function is now available for Windows Phone 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

Left("The cuckoo", 6) // Returns "The cu"
Left("ABC", 50) // Returns "ABC"
Left("AZELMA ") // Returns "AZELMA"

MyString is string = "Developing is child's play"
Left(MyString, 10) // Returns "Developing"

// Extract the bytes
MyBuffer is Buffer = "Developing is child's play"
Left(MyBuffer, 10) // Returns "Developing"

Syntax

Extracting the left part of a character string Hide the details

<Result> = Left(<Source string> [, <Length>])

<Result>: Character string

Left part of <Source String>. Corresponds to <Source String> if <Length> is greater than the length of <Source String>.
EOT if <Length> is negative. A WLanguage error occurs (non-fatal error). To find out the error details, use ErrorInfo.

<Source string>: Character string (with quotes)

Character string whose left part will be extracted. This string is not modified.

<Length>: Optional integer

Number of characters to extract. If this parameter is not specified, <Result> corresponds to <Source String> without the space characters on the right.
Versions 16 and later
This parameter is mandatory in Windows Phone.
New in version 16
This parameter is mandatory in Windows Phone.
This parameter is mandatory in Windows Phone.

Extracting the left part of a buffer Hide the details

<Result> = Left(<Source buffer> [, <Size>])

<Result>: Character string

Left part of <Source Buffer>. Corresponds to <Source Buffer> if <Size> is greater than the size of <Source Buffer>.
EOT if <Size> is 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 UNICODE format.

<Source buffer>: Buffer

Buffer whose left part will be extracted. This buffer is not modified.

<Size>: Optional integer

Number of bytes to extract. If this parameter is not specified, <Result> corresponds to <Source Buffer> without the space characters on the right.
In UNICODE, each character occupies two memory bytes. Therefore, the number of bytes is twice the number of characters.

Remarks

Left 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.

Reminder: 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.

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

Note: 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 for more details.

Operating mode in GO mode and at run time

In GO mode (simulation on the development computer), when extracting the left part of a buffer (syntax 2), <Length> 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"
Left(MyBuffer, 6)

The result is as follows:

in GO mode, returns "WINDEV".
at run time, returns "Win".

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

Component : wd250vm.dll