Merge pull request #194 from puripuri2100/update-ch03

3章をupdateした

Author: tatsuya6502

listings/ch03-common-programming-concepts/listing-03-01/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "functions"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]

listings/ch03-common-programming-concepts/listing-03-02/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "branches"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]

listings/ch03-common-programming-concepts/listing-03-02/src/main.rs

@@ -2,5 +2,6 @@ fn main() {
     let condition = true;
     let number = if condition { 5 } else { 6 };
 
+    // numberの値は、{}です
     println!("The value of number is: {}", number);
 }

listings/ch03-common-programming-concepts/listing-03-03/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "loops"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]

listings/ch03-common-programming-concepts/listing-03-03/src/main.rs

@@ -7,5 +7,6 @@ fn main() {
         number -= 1;
     }
 
+    // 発射！
     println!("LIFTOFF!!!");
 }

listings/ch03-common-programming-concepts/listing-03-04/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "loops"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]

listings/ch03-common-programming-concepts/listing-03-04/src/main.rs

@@ -3,6 +3,7 @@ fn main() {
     let mut index = 0;
 
     while index < 5 {
+        // 値は{}です
         println!("the value is: {}", a[index]);
 
         index += 1;

listings/ch03-common-programming-concepts/listing-03-05/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "loops"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]

listings/ch03-common-programming-concepts/listing-03-05/src/main.rs

@@ -1,7 +1,8 @@
 fn main() {
     let a = [10, 20, 30, 40, 50];
 
-    for element in a.iter() {
+    for element in a {
+        for element in a {
         println!("the value is: {}", element);
     }
 }

listings/ch03-common-programming-concepts/no-listing-01-variables-are-immutable/Cargo.toml

@@ -1,7 +1,6 @@
 [package]
 name = "variables"
 version = "0.1.0"
-authors = ["Your Name <you@example.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]