Difference between OpenGL ES3 and ES2 shader variables

Question

For OpenGL ES 3.0, I am wondering if we still use attribute/varying etc for variables. or we need to switch to in/out variables?

Answer 1

You need to switch to in/out if you move to the new GLSL version (#version 300 es). The spec documents the new storage qualifiers, and also specifically mentions:

When porting applications from OpenGL ES 2.0 to OpenGL ES 3.0, the following points should be noted: Not all language constructs present in v1.00 of the language are available in v3.00 e.g. attribute and varying qualifiers. However, the functionality of GLSL ES 3.00 is a super-set of GLSL ES 1.00.