Closets in Apartment Life are treated as objects, and are purchased in buy mode. However, closet objects are designed with the intent to be used as part of the structure of a house, rather than as a free-standing object.
Functionally, closets are the same as dressers. Clothes become available in closets after being purchased by a Sim on a community lot, though some custom content allows Sims to get new clothes while at home. Sims also receive a set of clothes when they age. Beginning with University, any career outfits a Sim receives are also available in a closet. Once an item of clothing is in a closet or dresser, it becomes available to all household members of the appropriate age and gender, for as long as the household continues to exist. When at least two items of a particular clothing type are available, the player can use the Plan Outfit interaction to choose one of them; if the Sim is wearing that type of clothing, he or she will change clothes.
There are two types of closets: "rack" closet objects, and in-wall closets. A closet rack is an object with a 1x1 footprint, available in a male or female variant (though both can be used by either gender), and priced at §75. Closet racks can be added to a custom-built closet, allowing the construction of large "walk-in closets." An in-wall closet is an object with a 2x1 footprint, which must be placed on an open stretch of wall at least two tiles wide. In-wall closets feature a sliding double door, available either with or without a mirror, and are priced at §1049 and §1050, respectively. In-wall closets can be used by Sims to WooHoo (including "Try for Baby"), and mirrored in-wall closets have a fully-functional mirror.