diff --git a/javascript/Javascript Expert/chapter11/findIndex.js b/javascript/Javascript Expert/chapter11/findIndex.js
new file mode 100644
index 0000000..f2c0bf9
--- /dev/null
+++ b/javascript/Javascript Expert/chapter11/findIndex.js	
@@ -0,0 +1,48 @@
+const randomIntNumbers = n => {
+  let transaktionen = [];
+  for (let i = 0; i < n; i++) {
+    const rndNum = Math.random() * 1000;
+    rndNum > Math.random() * 1000
+      ? transaktionen.push(Math.trunc(rndNum))
+      : transaktionen.push(-Math.trunc(rndNum));
+  }
+  return transaktionen;
+};
+
+const movements = randomIntNumbers(16);
+
+const account1 = {
+  owner: "David Aster",
+  movements: [200, 450, -400, 3000, -650, -130, 70, 1300],
+  interestRate: 1.2, // %
+  pin: 1111,
+};
+
+const account2 = {
+  owner: "Joanne Aster",
+  movements: [5000, 3400, -150, -790, -3210, -1000, 8500, -30],
+  interestRate: 1.5,
+  pin: 2222,
+};
+
+const account3 = {
+  owner: "Steven Schmidt",
+  movements: [200, -200, 340, -300, -20, 50, 400, -460],
+  interestRate: 0.7,
+  pin: 3333,
+};
+
+const account4 = {
+  owner: "Elvis Presley",
+  movements: [430, 1000, 700, 50, 90],
+  interestRate: 1,
+  pin: 4444,
+};
+
+const accounts = [account1, account2, account3, account4];
+
+const searchAccount = accounts.findIndex(function (account) {
+  return account.owner === "Elvis Presley";
+});
+
+console.log(searchAccount);
diff --git a/javascript/Javascript Expert/chapter11/flatAndFlatMap.js b/javascript/Javascript Expert/chapter11/flatAndFlatMap.js
new file mode 100644
index 0000000..7dff0f6
--- /dev/null
+++ b/javascript/Javascript Expert/chapter11/flatAndFlatMap.js	
@@ -0,0 +1,39 @@
+const arr = [1, 2, 3, [4], [5, 6], [7, 8, 9]];
+console.log(arr.flat(1));
+
+const deepArr = [1, [2, [3, 4], 5], [6, [7, 8], 9]]; // flat Methode stellt Werte eine Stufe höher um
+console.log(deepArr.flat());
+
+const account1 = {
+  owner: "David Aster",
+  movements: [200, 450, -400, 3000, -650, -130, 70, 1300],
+  interestRate: 1.2, // %
+  pin: 1111,
+};
+
+const account2 = {
+  owner: "Joanne Aster",
+  movements: [5000, 3400, -150, -790, -3210, -1000, 8500, -30],
+  interestRate: 1.5,
+  pin: 2222,
+};
+
+const account3 = {
+  owner: "Nika Aster",
+  movements: [200, -200, 340, -300, -20, 50, 400, -460],
+  interestRate: 0.7,
+  pin: 3333,
+};
+
+const account4 = {
+  owner: "Eva Aster",
+  movements: [430, 1000, 700, 50, 90],
+  interestRate: 1,
+  pin: 4444,
+};
+
+const accounts = [account1, account2, account3, account4];
+
+const accountsMovements = accounts.map(acc => acc.movements);
+const allMovements = accountsMovements.flat(); // gibt alle Transaktionen aus allen Accounts zurück(extrahiert bestehende Transaktionen, die in den Felder sind)
+const overallBalance = allMovements.reduce((acc, cur) => acc + cur); // Berechnung aller Transaktionen
diff --git a/javascript/Javascript Expert/chapter11/someAndEveryMethod.js b/javascript/Javascript Expert/chapter11/someAndEveryMethod.js
new file mode 100644
index 0000000..bb47ca9
--- /dev/null
+++ b/javascript/Javascript Expert/chapter11/someAndEveryMethod.js	
@@ -0,0 +1,29 @@
+const obst = ["apfel", "erdbeere", "mango", "banane", "orange"];
+
+function checkVerfuegbarkeit(obst, val) {
+  return obst.some(v => v === val);
+}
+
+console.log(checkVerfuegbarkeit(obst, "orange"));
+console.log(checkVerfuegbarkeit(obst, "heidelbeere"));
+
+const randomIntNumbers = n => {
+  let transaktionen = [];
+  for (let i = 0; i < n; i++) {
+    const rndNum = Math.random() * 1000;
+    rndNum > Math.random() * 1000
+      ? transaktionen.push(Math.trunc(rndNum))
+      : transaktionen.push(-Math.trunc(rndNum));
+  }
+  return transaktionen;
+};
+
+const deposits = randomIntNumbers(50);
+const anyDeposits = deposits.some(deposit => deposit > 0);
+console.log(anyDeposits);
+
+function isBigEnough(element, index, array) {
+  return element >= 10;
+}
+[12, 5, 8, 130, 44].every(isBigEnough); // false, weil da nich alle Werte mehr als 10 sind
+[12, 54, 18, 130, 44].every(isBigEnough); // true, weil da alle Werte der Bedienung "element > 10" entsprechen
diff --git a/javascript/Javascript Expert/chapter11/template.js b/javascript/Javascript Expert/chapter11/template.js
index 882d298..7b7636f 100644
--- a/javascript/Javascript Expert/chapter11/template.js	
+++ b/javascript/Javascript Expert/chapter11/template.js	
@@ -15,14 +15,14 @@ const account2 = {
 };
 
 const account3 = {
-  owner: "Nika Aster",
+  owner: "Steven Schmidt",
   movements: [200, -200, 340, -300, -20, 50, 400, -460],
   interestRate: 0.7,
   pin: 3333,
 };
 
 const account4 = {
-  owner: "Eva Aster",
+  owner: "Elvis Presley",
   movements: [430, 1000, 700, 50, 90],
   interestRate: 1,
   pin: 4444,