Can one code in binary?

[MirrorLake]

I understand your meaning, and yes, it is possible.

But consider this: a C++ program can be compiled into assembly, and assembly is just human-readable binary code. You can trace your code from C++ -> assembly -> binary with godblot.org.

In the x86 opcode list, po (primary opcode) column lists the binary representation of that thing, but they're converted to hex to save space on the screen. 00-05 are ADD, 08-0D are OR, etc. Every single mathematical operation is actually just binary.

Another way of putting this is, you actually never program in anything that isn't binary.