# JOIN Command
[GstarCAD 2022](Help%20System/GSTARCAD/2022/Index.md) → [Commands](Help%20System/GSTARCAD/2022/Commands/(Commands).md) → [J](Help%20System/GSTARCAD/2022/Commands/J/(J).md)
## Function Description:
This command is used to create a single object by connecting the endpoints of linear and curved objects.
Users can use this command to combine a series of finite linear and open
curved objects at their common endpoints to create a single 2D or 3D object. The generated object type is determined by the selected objects, the first selected object and coplanar objects or not.
****Note:**** Xlines, Rays and closed objects can not be joined.
## Command Access:
> **Icon:**
> 
> **Menu:** Modify \> Join
> **Ribbon:** Home \> Modify
> \> Join
> **Toolbar:** Modify \> Join
> **Command:** JOIN
> **Alias:** J
## Command Prompts:
Select source object or a merger of multiple objects
## **Source object**
Specifies a single source object to which you can join other objects. Press
Enter to select the objects to join. The following are rules:
- **Line**:
Only lines can be joined to the source line. The lines must be collinear with
the source line, but there can be a gap between two lines.
- **Polyline:**
Users can join a line and an arc to form a polyline. The selected line and arc must on the same plane in
the XY plane of UCS and share a common vertex.
- **Arc:**
An arc can be joined to the source arc. All the arcs must have the same radius and center point,
but there can be a gap between two arcs. It joins the selected arc along counterclockwise direction to the source arc. Select the Close option to convert
the source arc into a circle.
- **Elliptical arc:**
An elliptical arc can only be joined to the source elliptical arc. The elliptical arcs must
be coplanar and have the same major and minor axes, but there an be a gap between two elliptical arcs. Select the Close option to convert
the source elliptical arc into an ellipse.
- **Spline:** The source spline should share the common vertex with
the selected object. They can be on different planes. The resulting object
is a single spline.
- **Helix:**
The helix objects can join together to form a single spline. The selected two objects should share one common vertex.