Returns the left-most n characters of a string.
Informal Syntax:
Formal Syntax:
LEFT( In:=expression, L:=expression )
| Parameter | Type | Description |
|---|---|---|
| In | ANY_STRING | The input string. |
| L | ANY_INT | The number of characters to return. |
The function is overloaded and accepts either the STRING or WSTRING type for the In parameter.
The return value is a string consisting of the left-most L characters of string In.
The type of the string returned is the same as the In parameter.
If L is greater than the length of the In parameter, the function returns the entire string. If L is zero or negative, the function returns a zero length string.
| Example | Return Value |
|---|---|
| LEFT('', 2) | STRING#'' |
| LEFT('There', 3) | STRING#'The' |
| LEFT(In:="Ending", L:=3) | WSTRING#"End" |
IEC 61131-3 Second Edition: Table 29.2.
IEC 61131-3 Third Edition: Table 34.2.
Note: The function allows negative values for the L parameter. The IEC 61131-3 standard states this should be an error.
To learn about other String Functions.
To learn about other IEC 61131-3 Common Elements.
For the meaning of terms used in Fernhill SCADA.