Porovnávané verzie
porovnané s
Kľúč
- Tento riadok sa pridal
- Riadok je odstránený.
- Formátovanie sa zmenilo.
FIND_TRUE action
Function
The actions is searching for a value of a local variable, for which the given expression gets the value @TRUE.
Declaration
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FIND_TRUE _index, maxIndex, _retCode, find expression |
Parameters
| _index | in/out | Identifier (local variable) of Int type. Control variable for expression. |
| maxIndex | in | Identifier (local variable) of Int type. Maximal value of the control variable. |
| _retCode | out | Identifier of Int type - return code. |
| find expression | in | Expression of BOOL type. |
Description
The action progressively increases a value of the local control value _index by +1. It evaluates the expression find expression before each increasing of the value. If the expression gets the value @TRUE, the action is to be terminated and the control value _index contains the given value. If the expression is not to be evaluated successfully (invalid values, ...), the variable _retCode will contain the error type, otherwise _ERR_NO_ERROR. If the expression find expression does not get the value @TRUE within all permitted range, the value of the variable _index will be maxIndex+1 after the action termination.
It is necessary, to make the expression find expression dependent on a value of the control value. If not, the action generates the error _ERR_LOCAL_VAR_NFOUND.
As you can see be seen in the example, the action may be taken advantage for can be advantageously used when searching structures.
Example
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RECORD (SD.RecordDef) _struct INT _index INT _maxIndex INT _retCode .... ; search for a row containing the text "hello" in the column Text _index := 1 ; search from the first row _maxIndex := _struct\DIM FIND_TRUE _index, _maxIndex, _retCode, _struct[_index]^Text="hello" IF _retCode # _ERR_NO_ERROR THEN ; the error retCode occurred in row index ELSIF _index = _maxIndex+1 THEN ; required row not found ELSE ; the row_index contains the text "hello" in the column Text ENDIF |