all tests passed

index.js

@@ -15,8 +15,10 @@
 function find(array, callback) {
   for (let element of array) {
     // Write your code here.
+    if (callback(element)) return element
+  }
+  return undefined
   }
-}
 
 /**
  * Returns an array of all elements in the array that cause the callback to return `true`. If the array is empty or no elements cause the callback to return `true`, then return an empty array.
@@ -32,14 +34,15 @@ function find(array, callback) {
  *  filter([1, 2, 3], (element) => element < 0);
  *  //> []
  */
-function filter(array, callback) {
+function filter(array, callback){
   const result = [];
-  for (let element of array) {
+  for (let element of array)
     // Write your code here.
-  }
-  return result;
+    if (callback(element)) {
+      result.push(element)
+    }
+  return result
 }
-
 /**
  * Returns an array where each element is transformed by the callback. If the array is empty, return an empty array.
  * @param {*[]} array - An array of elements. Could be anything!
@@ -58,10 +61,10 @@ function map(array, callback) {
   const result = [];
   for (let element of array) {
     // Write your code here.
+    result.push(callback(element))
   }
-  return result;
+  return result
 }
-
 /**
  * Does not return anything. Passes each element of the array into the callback along with the index and the array, in that order.
  * @param {*[]} array - An array of elements. Could be anything!
@@ -78,6 +81,7 @@ function map(array, callback) {
 function forEach(array, callback) {
   for (let i = 0; i < array.length; i++) {
     // Write your code here.
+    callback(array[i], i, array)
   }
 }