scopes and shadowing

src/main.rs

@@ -1,20 +1,12 @@
-
-static BANNER: &str = "Welcome to Rust";
-
-const DIGEST_SIZE: usize = 3;
-const ZERO: Option<u8> = Some(42);
-
-fn compute_digest(text: &str) -> [u8; DIGEST_SIZE] {
-    let mut digest = [ZERO.unwrap_or(0); DIGEST_SIZE];
-    for (idx, &b) in text.as_bytes().iter().enumerate() {
-        digest[idx % DIGEST_SIZE] = digest[idx % DIGEST_SIZE].wrapping_add(b)
-    }
-    return digest;
-}
-
 fn main() {
-    println!("{BANNER}");
+    let a = 10;
+    println!("beginning a: {a}");
+    {
+        let a = "hello";
+        println!("inner a: {a}");
 
-    let digest = compute_digest("Hello");
+        let a = true;
-    println!("digest: {digest:?}");
+        println!("shadowed a: {a}");
+    }
+    println!("ending a: {a}");
 }