4 files changed, 15 insertions, 17 deletions
diff --git a/rustlings/exercises/09_strings/strings1.rs b/rustlings/exercises/09_strings/strings1.rs
index 6abdbb4..482e5de 100644
--- a/rustlings/exercises/09_strings/strings1.rs
+++ b/rustlings/exercises/09_strings/strings1.rs
@@ -1,6 +1,5 @@
-// TODO: Fix the compiler error without changing the function signature.
 fn current_favorite_color() -> String {
-    "blue"
+    String::from("blue")
 }
 
 fn main() {
diff --git a/rustlings/exercises/09_strings/strings2.rs b/rustlings/exercises/09_strings/strings2.rs
index 93d9cb6..b03094f 100644
--- a/rustlings/exercises/09_strings/strings2.rs
+++ b/rustlings/exercises/09_strings/strings2.rs
@@ -1,4 +1,3 @@
-// TODO: Fix the compiler error in the `main` function without changing this function.
 fn is_a_color_word(attempt: &str) -> bool {
     attempt == "green" || attempt == "blue" || attempt == "red"
 }
@@ -6,7 +5,7 @@ fn is_a_color_word(attempt: &str) -> bool {
 fn main() {
     let word = String::from("green"); // Don't change this line.
 
-    if is_a_color_word(word) {
+    if is_a_color_word(&word) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");
diff --git a/rustlings/exercises/09_strings/strings3.rs b/rustlings/exercises/09_strings/strings3.rs
index f5e45b0..3543ad5 100644
--- a/rustlings/exercises/09_strings/strings3.rs
+++ b/rustlings/exercises/09_strings/strings3.rs
@@ -1,13 +1,13 @@
 fn trim_me(input: &str) -> &str {
-    // TODO: Remove whitespace from both ends of a string.
+    input.trim()
 }
 
 fn compose_me(input: &str) -> String {
-    // TODO: Add " world!" to the string! There are multiple ways to do this.
+    String::from(input) + " world!"
 }
 
 fn replace_me(input: &str) -> String {
-    // TODO: Replace "cars" in the string with "balloons".
+    String::from(input).replace("cars", "balloons")
 }
 
 fn main() {
diff --git a/rustlings/exercises/09_strings/strings4.rs b/rustlings/exercises/09_strings/strings4.rs
index 4730726..3f7c5e7 100644
--- a/rustlings/exercises/09_strings/strings4.rs
+++ b/rustlings/exercises/09_strings/strings4.rs
@@ -13,25 +13,25 @@ fn string(arg: String) {
 // Your task is to replace `placeholder(…)` with either `string_slice(…)`
 // or `string(…)` depending on what you think each value is.
 fn main() {
-    placeholder("blue");
+    string_slice("blue");
 
-    placeholder("red".to_string());
+    string("red".to_string());
 
-    placeholder(String::from("hi"));
+    string(String::from("hi"));
 
-    placeholder("rust is fun!".to_owned());
+    string("rust is fun!".to_owned());
 
-    placeholder("nice weather".into());
+    string("nice weather".into());
 
-    placeholder(format!("Interpolation {}", "Station"));
+    string(format!("Interpolation {}", "Station"));
 
     // WARNING: This is byte indexing, not character indexing.
     // Character indexing can be done using `s.chars().nth(INDEX)`.
-    placeholder(&String::from("abc")[0..1]);
+    string_slice(&String::from("abc")[0..1]);
 
-    placeholder("  hello there ".trim());
+    string_slice("  hello there ".trim());
 
-    placeholder("Happy Monday!".replace("Mon", "Tues"));
+    string("Happy Monday!".replace("Mon", "Tues"));
 
-    placeholder("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }