To use a structure in your ESL program, you must first define a named structure type, then declare one or more structure variables of that type. In the structure type definition, you specify an identifier for the type, and the names and types of its fields, in order.

The name of a structure type must not be the same as the name of any other named part, such as a structure type, variable, or region defined in the same ESL program, or included in the program in an include file. The name you give a field must be unique within the structure type where you define the field, but more than one structure type in a program can contain the same field name.

The type of a field in a structure can be defined as an integer, float, or string. A field can also be itself a structure or an array. You cannot define a boolean field.

When you declare a structure variable, you specify a previously- defined named structure type, and an identifier for the variable.