# var Sets a variable (by name and value), or set of variables (from file or URL) in Ivy. Variables are case sensitive. Contrary to Ant properties, Ivy variables are mutable. But a problem with this is that you do not control when variables are substituted, and usually it is done as soon as possible. So changing the value of a variable will have no effect if it has already been substituted. Consequently, using this task is NOT recommended. See reference page for details about Ivy variables. ## Attributes
Attribute | Description | Required
--- | --- | ---
name | the name of the variable to set | No
value | the value of the variable to set | Yes when using the name attribute
file | the filename of the property file to load as Ivy variables | One of these, when not using the name attribute
url | the URL from which to read Ivy variables
prefix | Prefix to apply to variables. A dot (`.`) is appended to the prefix if not specified. | No
settingsRef | A reference to Ivy settings that must be used by this task (since 2.0) | No, defaults to `ivy.instance`.