Interactive C expression visualizer and sandbox

When I was learning C, I thought I understood the basics. I didn’t. I moved forward too fast and only later realized I had skipped over some landmines. Here are a few things I wish I had slowed down and really tested before moving on: I assumed `a++` and `a = a + 1` were always the same. They’re not. In isolation they look identical, but the moment you put them inside a larger expression, C starts caring about when the increment happens. That difference can quietly break logic without throwing any errors. I forgot that `%` only works on integers. I tried to treat it like a mathematical modulus that works everywhere. C is stricter than that. If your operands aren’t integers, `%` simply isn’t an option and the compiler won’t negotiate. I assumed division "just works." Coming from higher-level languages, I expected `5 / 2` to behave like math. In C, integer division discards the fractional part without apology. If both operands are integers, the result is an integer—no rounding, no warnings. I ignored parentheses more than I should have. Operator precedence exists, but trusting it blindly is a great way to write code that looks right and behaves wrong. Parentheses don’t just clarify intent for humans; they protect you from subtle logic errors. My advice to anyone learning C: If any of these feel even slightly fuzzy, stop and repeat the experiments. Write tiny programs. Print intermediate values. Break your own assumptions on purpose. C doesn’t forgive vague understanding—it rewards precision. This isn’t about being slow. It’s about building a foundation that won’t collapse later when the code gets real.