请问unity中怎么定义walkspeed？

Question

void Update () {

 

        Debug.Log("Horizontal value:" + Input.GetAxis("Horizontal"));

 

        Vector3 direction = Input.GetAxis("Horizontal") * transform.right +

            Input.GetAxis("Vertical") * transform.forward;

        transform.position = transform.position +

            walkSpeed * direction * Time.deltaTime;

 

    }