How Does The Semantic Analysis! (Demystifying Compilers, lesson 4) Work?

Semantic analysis is like when your teacher checks if you understood the meaning of a story, not just the words, but what they mean together.

Imagine you're writing a letter to your friend, and you say: "I went to the park with my cat, and we ate pizza." Your teacher might think, Wait, cats don’t eat pizza! That’s like semantic analysis in a compiler, it checks if things make sense together.

Think of the compiler as your friend who helps you write letters. First, they check spelling and grammar (that's syntax). Now, semantic analysis is when they read the letter carefully to see if everything makes sense, like checking if your cat really eats pizza or if you're talking about a dog instead.

Semantic analysis looks at things like:

• Are variables used correctly? Like using a name that hasn’t been introduced yet.
• Do functions match up with what they’re supposed to do?
• Are the types of things matching, like trying to put a square peg in a round hole.

It's like when your teacher says, “I know you wrote this letter, but I don’t believe it’s true.” The compiler is doing the same thing, checking if everything really makes sense.