heightForHeaderInSection

Height for header in section (tableView:heightForHeaderInSection:) is a UITableViewDelegate method used in iOS development to specify the height of a header for a given section in a table view. By implementing this method, a developer can customize header heights on a per-section basis, rather than using a single, global value.

Signature and return value: The method is declared as a table view delegate function with the signature: - (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section. It returns the height in points for the header of the specified section. A nonnegative value instructs the table view to allocate that much vertical space. Returning zero or a negative value may result in the header using a default height or being hidden, depending on the iOS version and table view configuration.

Usage and behavior: Implementing this method allows different sections to have headers of different heights, which is useful when sections contain headers with varying amounts of content. The header view itself can be provided by tableView:viewForHeaderInSection: or by the table view’s default header. The height value must be consistent with the header view’s dimensions to avoid layout issues.

Performance and dynamic heights: For performance with many sections or varying heights, developers may also implement tableView:estimatedHeightForHeaderInSection: to provide an estimate and enable smoother scrolling during layout. When using Auto Layout with a custom header view, the actual height can be determined by the header view’s constraints.

See also: tableView:viewForHeaderInSection, heightForFooterInSection, estimatedHeightForHeaderInSection.