# Declare a Dynstruct Variable

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To enable the structure to be defined at runtime, an empty dynamic structure variable must be declared at compile time, using the type DYNSTRUCT**:**

MAP1 ds, dynstruct   \! scalar dynamic structure

MAP1 DS2, DYNSTRUCT  \! another



As with other built-in types, the type name is case insensitive.

Dynstructs are similar to dynamic X variables (X,0), except that they may be associated with—i.e. bound to—a structure definition. Until then, the structure is considered "uninitialized". Once the dynstruct variable has been bound to a defined structure, it behaves like a fixed-length instance of that structure. See [Reference / Usage](referenceusagedynamic.md).