01_grundlagen/uebungen/u44_quersumme.html

@@ -24,7 +24,13 @@
 
       const number = 4566;
 
-      const getDigitSum = (n) => {};
+      const getDigitSum = (n) => {
+        const s = n
+          .toString() // => '4242'
+          .split('') // => ['4','2','4','2']
+          .reduce((n1, n2) => Number(n1) + Number(n2), 0);
+        return s;
+      };
 
       console.log(getDigitSum(4242)); //=> 12
       console.log(getDigitSum('13')); //=> 4

01_grundlagen/uebungen/u45_quersummen-sortiert.html

@@ -24,15 +24,24 @@
 
       const numbers = [99, 5, 8, 12, 111, 123];
 
-      const getDigitSum = (n) => {};
+      const getDigitSum = (n) => {
+        const s = n
+          .toString() // => '4242'
+          .split('') // => ['4','2','4','2']
+          .reduce((n1, n2) => Number(n1) + Number(n2), 0);
+        return s;
+      };
 
-      const getSortedArrayByDigitSum = (numbers) => {};
+      const getSortedArrayByDigitSum = (numbers) => {
+        return [...numbers].sort((a, b) => {
+          return getDigitSum(a) - getDigitSum(b);
+        });
+      };
+
+      console.log('numbers: ', numbers);
 
       console.log(getSortedArrayByDigitSum([4, 12])); //=> [12, 4]
-
       console.log(getSortedArrayByDigitSum(numbers)); //=> [12, 111, 5, 123, 8, 99]
-
-      console.log(numbers);
     </script>
   </body>
 </html>