Modifying Function Parameters › Defining Function Parameters › Using Arrays as Parameters

Using Arrays as Parameters

You can create elements in an array that are similar to parameter definitions, and you can pass certain parameters as an array. For example, multiple instances of data can be passed within the parameter.

By passing a parameter as an array, multiple instances of data can be passed in or out in a single call to a function. For example, if a customer record structure is defined in the Customer array on the *Arrays file, you can use that array to define a parameter to an EXCEXTFUN or EXCUSRPGM being passed as RCD (ARRAY). Anywhere from a few to thousands of customer records can be passed in that one parameter in one single function call.

Arrays are defined over the *Arrays file and can be defined to contain any subset of the fields in the model. Arrays can also be specified as parameters to any function. Using arrays allows you to define any subset of fields as parameters to any function. Do this by creating an array definition with the appropriate field and specifying it as a parameter entry. This process is similar to using structure files for parameter lists but unlike structure files, it is under the control of *PGMR.

Notes:

• With this process, you use the array to supply a parameter definition and not the data.
• When generating functions using SQL, an array used to define the parameters for CHGOBJ or CRTOBJ must have the fields defined in the same order as the update access path.

You can pass an array as a parameter using one of two methods:

• Multiple-instance array parameter: Describes when a parameter is passed as an array (when the Pass as Array flag is set to 'Y'). The parameter contains multiple instances of data, where each instance contains all the fields which are individually specified as parameters using the parameter details display.
• Single-instance array parameter: Describes when a parameter defined using an array is not passed as an array (when the Pass as Array flag is not available or is set to blank). The parameter contains all the fields which are individually specified as parameters using the parameter details display.

For more information about arrays, see the chapter "Defining Arrays" in the Building Access Paths Guide.