martin.godwin

src/services/array-functions.js

@@ -1,57 +1,83 @@
 
 //in the function map, create a new array and store in a variable
-//loop theArray and call the fnc for each thing in the array, 
+//loop theArray and call the fnc for each thing in the array,
 //     passing in the item from the current loop into the call to fnc
 //add the returned value from fnc to the new array
 //return the new array
 export function map(theArray, fnc){
-
+  let newArray = [];
+  for(let i = 0; i < theArray.length; i++) {
+    newArray.push(fnc(theArray[i]));
+  }
+  return newArray;
 }
 
 //create a new array
-//loop theArray and call the fnc for each thing in the array, 
+//loop theArray and call the fnc for each thing in the array,
 //     passing in the item from the current loop
 //fnc will return true or false, if true add the item to the new array else do not
 //return the new array
 export function filter(theArray, fnc){
-
+  let newArray = [];
+  for(let i = 0; i < theArray.length; i++) {
+    if(fnc(theArray[i])) {
+      newArray.push(theArray[i]);
+    }
+  }
+  return newArray;
 }
 
 
-//loop theArray and call the fnc for each thing in the array, 
+//loop theArray and call the fnc for each thing in the array,
 //     passing in the item from the current loop
-//fnc will return true or false, if true return the item 
+//fnc will return true or false, if true return the item
 //return null
 export function find(theArray, fnc){
-
+  for(let i = 0; i < theArray.length; i++) {
+    if (fnc(theArray[i])) {
+      return true;
+    }
+  }
 }
 
 
 //return the last item in theArray
 export function findLast(theArray){
-
+ let last = theArray[theArray.length -1];
+  return last;
 }
 
 //return the first element of the array
 export function head(theArray){
-
+  let first = theArray[0];
+  return first;
 }
 
 //create a new array
 //loop theArray in reverse order
 //add the item from each loop to the new array
 //return the new array
 export function reverse(theArray){
-
+  let newArray = [];
+  for(let i = theArray.length -1; i >= 0; i--) {
+    newArray.push(theArray[i]);
+  }
+  return newArray;
 }
 
+
 //create a new array
 //loop theArray
 //add the item from each loop to the new array except the first item
 //return the new array
 export function tail(theArray){
+  let newArray = [];
+  for(let i = 1; i < theArray.length; i++) {
+    newArray.push(theArray[i]);
+    }
+    return newArray;
+  }
 
-}
 
 //implement the most basic sorting algorithm there is
 //assume the array will always have numbers
@@ -64,5 +90,21 @@ export function tail(theArray){
 //after each for loop check the variable, if true, continue the while loop
 //if false return theArray
 export function sort(theArray){
-
-}
+  let arr = theArray;
+  let sorted;
+  while (!sorted) {
+    sorted = true;
+    for (let i = 0; i < arr.length -1; i++) {
+      if (arr[i] > arr[i +1]) {
+        sorted = false;
+        let temp;
+        temp = arr[i];
+        arr[i] = arr[i + 1];
+        arr[i + 1] = temp;
+      }
+    }
+    if (sorted) {
+      return arr;
+    }
+  }
+}

src/tests/array-functions.test.js

@@ -1,6 +1,6 @@
-import {map,filter,find,findLast} from "../services/array-functions";
+import {map,filter,find,findLast,reverse,tail,head,sort} from "../services/array-functions";
 const names = ["Jon","Bob","Ted","Barney","Lilly","Robin","Saul","Axe"];
-const myNumbers = [4,3,55,22,99,1913,7,5,4,2,1];
+const myNumbers = [3,55,22,99,1913,7,5,4,2,1];
 
 function addHello(name){
   return "Hello " + name;
@@ -44,14 +44,34 @@ describe("sort", () => {
 
 //filter should return an array with names of length 3
 //["Jon","Bob","Ted","Axe"]
-
+describe("filter", () => {
+  it("should return an array with names of length 3", () => {
+    expect(filter(names, findThree)).toEqual(["Jon","Bob","Ted","Axe"]);
+  });
+});
 //find should find one name of "Barney"
-
+describe("find", () => {
+  it("should find one name of 'Barney'", () => {
+    expect(find(names, findBarney)).toEqual(true);
+  });
+});
 //findLast should find the last name of "Axe"
-
+describe("findLast", () => {
+  it("should find the name of 'Axe'", () => {
+    expect(findLast(names, findLast)).toEqual('Axe');
+  });
+});
 //reverse should return an array with the elements in the opposite order
 //["Axe","Saul","Robin","Lilly","Barney","Ted","Bob","Jon"]
+describe("reverse", () => {
+  it("should return an array with the elements in the opposite order", () => {
+    expect(reverse(names, reverse)).toEqual(["Axe","Saul","Robin","Lilly","Barney","Ted","Bob","Jon"]);
+  });
+});
 //tail should return all elements in an array except the first one
 //[Bob","Ted","Barney","Lilly","Robin","Saul","Axe"];
-
-
+describe("tail", () => {
+  it("should return all elements in an array except the first one", () => {
+    expect(tail(names, tail)).toEqual(["Bob","Ted","Barney","Lilly","Robin","Saul","Axe"]);
+  });
+});

src/tests/calculations.test.js

@@ -1,7 +1,25 @@
-import {add, subtract, multiply,divide} from "../services/calculations";
+import {add, subtract, multiple,divide} from "../services/calculations";
 
 describe("add", () => {
   it("should add 1 and 2 and return 3", () => {
     expect(add(1, 2)).toBe(3);
   });
 });
+
+describe("subtract", () => {
+  it("should subtract 1 from 2 and return 1", () => {
+    expect(subtract(2, 1)).toBe(1);
+  });
+});
+
+describe("multiple", () => {
+  it("should multiply 3 by 5 and return 15", () => {
+    expect(multiple(3, 5)).toBe(15);
+  });
+});
+
+describe("divide", () => {
+  it("should divide 4 by 2 and return 2", () => {
+    expect(divide(4, 2)).toBe(2);
+  });
+});