02_advanced/uebungen/u21_pokemon-evolution/index.html

@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+<!doctype html>
 <html lang="de">
   <head>
     <meta charset="UTF-8" />
@@ -41,17 +41,42 @@
         ['Dratini', 'Dragonair', 'Dragonite'],
       ];
 
-      const stagesFor = (pokemon) => {};
+      const stagesFor = (pokemon) => {
+        const stages = evolutionStages.find((stages) => stages.includes(pokemon));
+        return stages ? stages : [];
+      };
 
-      const stagesAfter = (pokemon) => {};
+      const stagesAfter = (pokemon) => {
+        const stages = stagesFor(pokemon);
+        const index = stages.indexOf(pokemon);
 
-      const stagesBefore = (pokemon) => {};
+        // wenn nicht gefunden
+        if (index === -1) return [];
 
+        return stages.slice(index + 1);
+      };
+
+      const stagesBefore = (pokemon) => {
+        const stages = stagesFor(pokemon);
+        const index = stages.indexOf(pokemon);
+
+        // wenn nicht gefunden
+        if (index === -1) return [];
+
+        return stages.slice(0, index);
+      };
+
+      console.log(stagesFor('Bulbasaur')); // => undefined
       console.log(stagesFor('Vulpix')); // => [ 'Vulpix', 'Ninetales' ]
+
       console.log(stagesAfter('Dratini')); // => [ 'Dragonair', 'Dragonite' ]
+      console.log(stagesAfter('Bulbasaur')); // => undefined
+      console.log(stagesAfter('Dragonite')); // => []
+
       console.log(stagesBefore('Pidgeot')); // => [ 'Pidgey', 'Pidgeotto' ]
       console.log(stagesBefore('Dragonair')); // => [ 'Dratini' ]
-      console.log(stagesBefore('Pidgey')); // => [  ]
+
+      console.log(stagesBefore('Pidgey')); // => []
       console.log(stagesBefore('Pidgeot')); // =>  ['Pidgey', 'Pidgeotto']
     </script>
   </body>