Guys help me! How to use namespaces here? Is it working here at all?

Question

so, i created some namespace with some data, here in app and saved it. next, i am created another file, wrote "using MyNamespace;" and... nothing!:-) Compile error - data of my namespace isn`t visible. What‘s up? im did something wrong or just custom namespaces not working here?
p.s. hello from Russia. hope u can understand my English:-):-):-)

Answer 1

Codeplayground cannot find other codes, you'll need to use a different compiler or create the namespaces in the same file.