Expressions
In 4GL, an expression can determine the value of a form component or can be a condition that can be evaluated to "True" or "False." An expression contains values, is a value, or produces values through processing.
An expression consists of a combination of operators, such as logical or arithmetic operators, and operands, which can be of many types. Expressions make up statements, which in turn make up 4GL specifications. All the operators and functions of the DBMS are available for use in 4GL expressions. These expressions include:
• Literals and constants (named literals)
• Simple fields and table-field columns
• Local and global variables
• Records and arrays based on forms, table fields, and tables
• Database access through query statements
• Procedures and values returned by procedures
• Numeric and string expressions
• Logical expressions
You can use expressions to substitute values for processing while your application is running.
Last modified date: 04/03/2024