Another update from ingydotnet^djgoku

Task/Loops-Nested/JavaScript/loops-nested-2.js

@@ -0,0 +1,43 @@
+var lst = [[2, 12, 10, 4], [18, 11, 9, 3], [14, 15, 7, 17], [6, 19, 8, 13], [1,
+  20, 16, 5]];
+
+var takeWhile = function (lst, fnTest) {
+    'use strict';
+    var varHead = lst.length ? lst[0] : null;
+
+    return varHead ? (
+      fnTest(varHead) ? [varHead].concat(
+        takeWhile(lst.slice(1), fnTest)
+      ) : []
+    ) : []
+  },
+
+  // The takeWhile function terminates when notTwenty(n) returns false
+  notTwenty = function (n) {
+    return n !== 20;
+  },
+
+  // Leftward groups containing no 20
+  // takeWhile nested within takeWhile
+  lstChecked = takeWhile(lst, function (group) {
+    return takeWhile(
+      group,
+      notTwenty
+    ).length === 4;
+  });
+
+
+// Return the trail of numbers preceding 20 from a composable expression
+
+console.log(
+  // Numbers before 20 in a group in which it was found
+  lstChecked.concat(
+    takeWhile(
+      lst[lstChecked.length], notTwenty
+    )
+  )
+  // flattened
+  .reduce(function (a, x) {
+    return a.concat(x);
+  }).join('\n')
+);

Task/Loops-Nested/JavaScript/loops-nested-3.js

@@ -0,0 +1,21 @@
+2
+12
+10
+4
+18
+11
+9
+3
+14
+15
+7
+17
+6
+19
+8
+13
+6
+19
+8
+13
+1