finished chaper 3

branches/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "branches"
+version = "0.1.0"

branches/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "branches"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

branches/src/main.rs

@@ -0,0 +1,46 @@
+fn main() {
+    let number = 3;
+    if number < 5 {
+        println!("condition was true");
+    } else {
+        println!("condition was false");
+    }
+
+    let mut counter = 0;
+    let result = loop {
+        counter += 1;
+
+        if counter == 10 {
+            break counter * 2;
+        }
+    };
+    println!("{result}result");
+
+
+
+    let mut count = 0;
+    'counting_up: loop {
+        println!("count = {count}");
+        let mut remaining = 10;
+        loop {
+            println!("remaining = {remaining}");
+            if remaining == 9 {
+                break;
+            }
+            if count == 2 {
+                break 'counting_up;
+            }
+            remaining -= 1;
+        }
+        count += 1;
+    }
+    println!("{count} count");
+
+
+    // for number in (1..4).rev() { // exclusive
+    for number in (1..=4).rev() { // inclusive
+        println!("{number}!");
+    }
+    println!("liftoff");
+
+}

variables/src/main.rs

@@ -1,3 +1,5 @@
+use std::io;
+
 fn main() {
     let x = 5;
     let x = x + 1;
@@ -15,5 +17,29 @@ fn main() {
     println!("fy: {fy}");
 
 
-    // last page 39
+
+    let a = [1,2,3,4,5];
+    let mut index = String::new();
+    io::stdin()
+        .read_line(&mut index)
+        .expect("failed");
+
+    let index :usize = index.trim().parse().expect("not a number)");
+    let element = a[index];
+    println!("{index} is {element}");
+
+    let mut y = {
+        let x = 3;
+        x + 1
+    };
+    println!("{y}");
+    y = five();
+    println!("{y}");
+
 }
+
+
+
+fn five () -> i32 {
+    5
+}