Calculations test for add, subtract, multiply, and divide complete

src/services/array-functions.js

@@ -8,52 +8,78 @@
 //add the returned value from fnc to the new array
 //after looping, return the new array
 export function map(theArray, fnc){
-
-}
+  const myNewArray = [];
+  for (let i=0; i<theArray.length; i++){
+    const temp = theArray[i];
+    const returned = fnc(temp);
+    myNewArray.push(returned);
+  };
+  return myNewArray;
+};
 
 //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){
-
-}
-
-
-//loop theArray and call the fnc for each thing in the array, 
+  let newArray = [];
+  for (let i=0;i<theArray.length;i++) {
+    const value = fnc(theArray[i]);
+    if(value){
+      newArray.push(theArray[i])
+    };
+  };
+  return newArray;
+};
+
+
+//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++) {
+    const bool = fnc(theArray[i]);
+    if(bool){
+      return theArray[i];
+    };
+  };
+};
 
 
 //return the last item in theArray
 export function findLast(theArray){
-
-}
+  return theArray[theArray.length-1];
+};
 
 //return the first element of the array
 export function head(theArray){
-
+  return theArray[0];
 }
 
 //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 reverseArray = [];
+  for (let i = theArray.length-1; i>=0; i--){
+    reverseArray.push(theArray[i]);
+  }
+  return reverseArray;
 }
 
 //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
@@ -67,5 +93,19 @@ 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 swap = false;
+  for(let i=0;i<theArray.length;i++) {
+    if(theArray[i] > theArray[i+1]) {
+      let temp = theArray[i];
+      theArray[i] = theArray[i+1]
+      theArray[i+1] = temp;
+      swap = true;
+    }
+  }
+  if (swap) {
+    swap = false;
+    return sort(theArray);
+  } else {
+    return theArray;
+  }
 }

src/tests/array-functions.test.js

@@ -1,4 +1,4 @@
-import {map,filter,find,findLast} from "../services/array-functions";
+import {map,filter,find,findLast,head,sort,reverse,tail} 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];
 
@@ -44,14 +44,48 @@ 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(
+      "Barney"
+    );
+  });
+});
 
 //findLast should find the last name of "Axe"
+describe("findLast", () => {
+  it("should find the last name in the array - Axe", () => {
+    expect(findLast(names)).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 elemens in the opposite order", () => {
+    expect(reverse(names)).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)).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 3 and return 2", () => {
+    expect(subtract(3,1)).toBe(2);
+  })
+});
+
+describe("multiply", () => {
+  it("should multiply 2 and 3 and return 6", () => {
+    expect(multiple(2,3)).toBe(6);
+  });
+});
+
+describe("divide", () => {
+  it("should divide 2 from 6 and return 3", () => {
+    expect(divide(6,2)).toBe(3);
+  });
+});