Structures

 

Structures are declared with the BASED attribute, and so do not occupy any storage unless the program declares one or more instances of a structure.

An instance of a structure can be declared using the like attribute, for example:

dcl my_mqmd       like MQMD;  /* one instance */
dcl my_other_mqmd like MQMD;  /* another one */

The structure fields are declared with the INITIAL attribute; when the like attribute is used to declare an instance of a structure, that instance inherits the initial values defined for that structure. You need to set only those fields where the value required is different from the initial value.

PL/I is not sensitive to case, and so the names of calls, structure fields, and constants can be coded in lowercase, uppercase, or mixed case.

 

Parent topic:

Coding in PL/I

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