lecture 02

lectures/02/src/vectors.rs

@@ -0,0 +1,47 @@
+pub fn run() {
+    println!("VECTORS");
+    let v = vec![3, 2, 7, 6, 8]; // macro for creating vector with known type
+    println!("{v:?}");
+
+    for i in 0..v.len() {
+        println!("{}", v[i]);
+    }
+
+    // x has typ &i32
+    // for x in &v {
+    //     println!("{x}");
+    // }
+
+    // x hsa type i32
+    // for x in v {         // this moves v
+    //     println!("{x}");
+    // }
+
+    // println!("{v:?}"); // ERROR v is already moved
+
+    let mut v = Vec::new();
+    for i in 0..10 {
+        v.push(i);
+    }
+
+    double(&mut v);
+    println!("{v:?}");
+
+    triple(&mut v); // you can pass vectors as slices also
+    println!("{v:?}");
+
+    triple(&mut v[1..4]); // can create sub slices
+    println!("{v:?}");
+}
+
+fn double(v: &mut Vec<i32>) {
+    for x in v {
+        *x *= 2
+    }
+}
+
+fn triple(s: &mut [i32]) {
+    for x in s {
+        *x *= 3
+    }
+}