isUnread

isUnread is a common property or predicate used in software systems to indicate whether an item has not been read by a user. It is typically a boolean value or a function that returns a boolean. The concept is widely used for messages, emails, notifications, and forum threads, serving as a cue for user attention and for presenting visual indicators such as bold titles or notification badges.

Semantics and scope: isUnread represents the unread state of a single item. In many applications, a user can have separate unread states for items that exist in different contexts, such as messages in a multi-conversation inbox or notifications from multiple services. Some implementations store the flag directly on the item (for example, a boolean is_unread column in a database record). Others derive the status from timestamps, such as lastViewedAt versus createdAt, where an item is considered unread if lastViewedAt is before createdAt or is null.

Usage: isUnread is commonly used to filter or sort lists, to trigger visual cues, and to drive notification badges. In code, it is accessed as a method or property (for example, item.isUnread() or item.unread). Correct use often involves ensuring consistent state across devices and sessions, and aligning with user expectations when items are marked as read or unread.

Variants and considerations: In multi-user or cross-device environments, unread status may be per-user rather than global, requiring a separate storage of read receipts or per-user flags. Performance and privacy considerations may affect how isUnread is computed or synchronized.

See also: read status, read receipt, notification badge.