Do String borrow better

variables/src/main.rs

@@ -11,7 +11,7 @@ fn main() {
                 command = arg;
                 continue;
             }
-            _ => command_args.push(arg.as_str().to_string()),
+            _ => command_args.push(arg.clone()),
         }
     }
 
@@ -21,7 +21,7 @@ fn main() {
                 eprintln!("ERROR: missing a value to convert");
                 process::exit(1);
             }
-            temp_convert(command_args[0].as_str().to_string())
+            temp_convert(&command_args[0])
         }
         "fib" => {
             if command_args.len() < 1 {
@@ -58,7 +58,7 @@ fn redefine_x() {
     println!("The value of x is: {}", x);
 }
 
-fn temp_convert(to_convert: String) {
+fn temp_convert(to_convert: &String) {
     let to_convert = to_convert.to_lowercase();
     if to_convert.ends_with("c") {
         let c: f32 = to_convert