iReport Ultimate Guide - Nimsoft Library

Fields, Parameters, and VariablesCHAPTER 6FIELDS, PARAMETERS, AND VARIABLESIn a report, there are three groups of objects that can store values:• Fields• Parameters• VariablesiReport uses these objects in data source queries. In order to use these objects in a report, they must be declared with a discretetype that corresponds to a Java class, such as String or Double. After they have been declared in a report design, the objectscan be modified or updated during the report generation process.Figure 6-1Report objects in outline viewAfter they have been declared, they can be managed using the Report Inspector view. In the Report Inspector you can modifyor remove objects and declare new objects, as well.This chapter has the following sections:• Working with Fields• Working with Parameters• Working with Variables• Evaluating Elements During Report Generation95