what is the index and level properties of task used for?

Hi,

What is the use of the $level and $task properties of task object and is there any relationship between them?

Hi,
these are the precalculated service properties that are used by the component.
$level contains a tasks level in the hierarchy, the same value can be calculated by this method docs.dhtmlx.com/gantt/api__gantt … level.html
$index is an order of a task row in a grid (regardless of level), can be recalculated using this method docs.dhtmlx.com/gantt/api__gantt … index.html