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Version: 7.0

CONCAT operator

The CONCAT operator creates a property that implements a string concatenation.

Syntax​

CONCAT separatorExpr, concatExpr1, ..., concatExprN

Description​

The CONCAT operator creates a property that concatenates the values of concatExpr1, ..., concatExprN, in the order written, placing the separatorExpr separator between them. The handling of the separator and of NULL operands follows the CONCAT concatenation.

The first operand is always the separator, even when it is meant as a prefix: CONCAT 'Total: ', 'a', 'b' gives 'aTotal: b', not 'Total: ab'. Text at the start or at the end of the result is written as an ordinary operand with an empty separator (CONCAT '', 'Total: ', 'a', 'b') or added with the + operator ('Total: ' + CONCAT ', ', 'a', 'b').

Parameters​

  • separatorExpr

    Expression whose value is used as the separator. It is most often a string literal but may be any string expression.

  • concatExpr1, ..., concatExprN

    Expressions whose values are concatenated. At least one operand must be specified.

Examples​

CLASS Person;
firstName = DATA STRING[100] (Person);
middleName = DATA STRING[100] (Person);
lastName = DATA STRING[100] (Person);

// if some part of the name is not specified, then this part will be skipped along with a space
fullName(Person p) = CONCAT ' ', firstName(p), middleName(p), lastName(p);     

// the heading is a separate operand with an empty separator: the first operand of CONCAT is always the separator,
// and CONCAT 'Person: ', firstName(p), lastName(p) would give 'JohnPerson: Smith'
caption(Person p) = CONCAT '', 'Person: ', fullName(p);