Transform.eulerAngles

Description

The rotation as Euler angles in degrees.

The x, y, and z angles represent a rotation z degrees around the z axis, x degrees around the x axis, and y degrees around the y axis.

Only use this variable to read and set the angles to absolute values. Don't increment them, as it will fail when the angle exceeds 360 degrees. Use Transform.Rotate instead.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public float yRotation = 5.0F;
    void Update() {
        yRotation += Input.GetAxis("Horizontal");
        transform.eulerAngles = new Vector3(10, yRotation, 0);
    }
    void Example() {
        print(transform.eulerAngles.x);
        print(transform.eulerAngles.y);
        print(transform.eulerAngles.z);
    }
}

Do not set one of the eulerAngles axis separately (eg. eulerAngles.x = 10; ) since this will lead to drift and undesired rotations. When setting them to a new value set them all at once as shown above. Unity will convert the angles to and from the rotation stored in Transform.rotation.