how to access camera from another object

Questions & Answers
1

My script is attached to a character controller.
And i declared

public Camera camera;

in class.
In update function i given

if(Input.GetMouseButtonDown(0)){ 
Ray ray = camera.ScreenPointToRay(Input.mousePosition);	
if (Physics.Raycast (ray, out hit3, 400.0F)){
    print(hit3.collider.gameObject.name); 
}
}

But i am getting error

"UnassignedReferenceException: 
The variable camera of 'characterScript' has not been assigned.
You probably need to assign the camera variable of the 
characterScript script in the inspector."

Help me with a good solution.
Thanks in Advance

2

you can use:

Camera.mainCamera

But make sure your camera has the “MainCamera” Tag