Opengl shading

I am learning different OpenGL shading examples. I am able to implement flat and gouraud shading. Can anyone help me with a simple example on phong shading? Thak you.

Did you try to google with right keywords? There’s a plenty of tutorials on the net. For example:

Does it mean that phong shading can’t be implemented without GLSL i.e. just with OpenGL?

Legacy OpenGL (i.e. fixed functionality) supports only two types of shading: flat and Gouraud (i.e. “smooth”). The desired shading model is set by glShadeModel() function call. For anything else (like Phong shading) you need GLSL.