feat: add strings5.rs exercise

exercises/strings/strings5.rs

@@ -0,0 +1,30 @@
+// strings5.rs
+// println!, print!, and format! use the same system for created formatted text.
+// Make all tests pass by only changing the first parameter to each format! call.
+// Execute `rustlings hint strings5` or use the `hint` watch subcommand for a hint.
+
+// I AM NOT DONE
+
+#[cfg(test)]
+mod tests {
+
+    //TODO only change first parameter in each format! call.
+    #[test]
+    fn greeting() {
+        let world = "world";
+        //The basic usage you probably saw used in println! statements
+        assert_eq!(format!("Hello, !", world), "Hello, world!");
+
+        //There is a way to get the same result inline, without passing world as an argument.
+        assert_eq!(format!("Hello, {}!"), "Hello, world!");
+    }
+
+    #[test]
+    fn bond() {
+        //You can use the same argument multiple times,
+        //as well as specicfy which argument should be used for a given {} placeholder.
+        assert_eq!(format!("My name is {}. {} {}.", "James", "Bond"), "My name is Bond. James Bond.");
+        //There are also ways to specify how numbers should be displayed.
+        assert_eq!(format!("My code number is {}.", 7), "My code number is 007.");
+    }
+}

info.toml

@@ -460,6 +460,12 @@ path = "exercises/strings/strings4.rs"
 mode = "compile"
 hint = "No hints this time ;)"
 
+[[exercises]]
+name = "strings5"
+path = "exercises/strings/strings5.rs"
+mode = "test"
+hint = "You can find documentation for println! / format! syntax at https://doc.rust-lang.org/std/fmt/index.html"
+
 # MODULES
 
 [[exercises]]