Operator Reference
tuple_is_string (Operator)
tuple_is_string — Test if the internal representation of a tuple is of type string.
Signature
Description
tuple_is_string tests if the internal representation of the
input tuple T is of type string. In that case the value
1 (true) is returned in IsString, otherwise the value
0 (false) is returned. If a tuple consists of string
elements only, IsString can nevertheless be 0 in case the internal
representation is H_TYPE_MIXED; see tuple_type for details.
Exception: Empty input tuple
If the input tuple is empty, the operator returns 1.
HDevelop In-line Operation
HDevelop provides an in-line operation for tuple_is_string,
which can be used in an expression in the following syntax:
IsString := is_string(T)
Attention
Even if all tuple elements are of type string,
tuple_is_string returns 0 (false) if the internal representation
of the tuple is of type H_TYPE_MIXED. To test if the elements of the
tuple are of type string the operator tuple_is_string_elem
should be used.
Execution Information
- Multithreading type: independent (runs in parallel even with exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
Parameters
T (input_control) tuple(-array) → (string / real / integer / handle)
Input tuple.
IsString (output_control) number → (integer)
Is the input tuple of type string?
Example (HDevelop)
tuple_is_string ([3.1416,'pi',3], IsStringA) * IsStringA = false tuple_is_string (['a','b','111'], IsStringB) * IsStringB = true tuple_is_string ([], IsStringC) * IsStringC = true
Result
If the parameters are valid, the operator
tuple_is_string returns the value 2 (
H_MSG_TRUE)
.
Alternatives
tuple_type,
tuple_is_number,
tuple_is_string_elem
See also
tuple_is_int,
tuple_is_real,
tuple_is_handle
Module
Foundation