TheOdinProject · mao-sz · Sep 4, 2026 · Sep 2, 2026 · Sep 4, 2026
diff --git a/README.md b/README.md
@@ -19,7 +19,7 @@ If you have a suggestion to improve an exercise, an idea for a new exercise, or
    - A markdown file with a description of the task, an empty (or mostly empty) JavaScript file, and a set of tests.
    - A `solutions` directory that contains an example solution and the same test file with all of the tests unskipped.
 
-   To complete an exercise, you will need to go to the exercise directory with `cd <path to file>` in the terminal and run `npm test exerciseName.spec.js`. For example, to go to the first Foundations exercise "helloWorld", you need to `cd foundations/01_helloWorld` then run `npm test helloWorld.spec.js`. This should run the test file and show you the output. When you run a test for the first time, it will fail. This is by design! You must open the exercise file and write the code needed to get the test to pass.
+   To complete an exercise, you will need to go to the exercise directory with `cd <path to file>` in the terminal and run `npm test exerciseName.spec.js`. For example, to go to the first Foundations exercise "helloWorld", you need to `cd foundations/data_types_and_conditionals/01_helloWorld` then run `npm test helloWorld.spec.js`. This should run the test file and show you the output. When you run a test for the first time, it will fail. This is by design! You must open the exercise file and write the code needed to get the test to pass.
 1. Some of the exercises have test conditions defined in their spec file as `test.skip` instead of `test`. This is intentional. Once all `test` cases pass, you will change the next `test.skip` to `test` and test your code again. You will do this until all conditions are satisfied. **All tests must pass at the same time**, and you should not have any instances of `test.skip` in the spec file when you are finished with an exercise.
 1. Once you successfully finish an exercise, check the `solutions` directory within each exercise.
    - You should not be checking the solution for an exercise until you finish it!

diff --git a/foundations/01_helloWorld/README.md → ..._and_conditionals/01_helloWorld/README.md b/foundations/01_helloWorld/README.md → ..._and_conditionals/01_helloWorld/README.md
diff --git a/foundations/01_helloWorld/helloWorld.js → ..._conditionals/01_helloWorld/helloWorld.js b/foundations/01_helloWorld/helloWorld.js → ..._conditionals/01_helloWorld/helloWorld.js
diff --git a/foundations/01_helloWorld/helloWorld.spec.js → ...itionals/01_helloWorld/helloWorld.spec.js b/foundations/01_helloWorld/helloWorld.spec.js → ...itionals/01_helloWorld/helloWorld.spec.js
diff --git a/...elloWorld/solution/helloWorld-solution.js → ...elloWorld/solution/helloWorld-solution.js b/...elloWorld/solution/helloWorld-solution.js → ...elloWorld/solution/helloWorld-solution.js
diff --git a/...orld/solution/helloWorld-solution.spec.js → ...orld/solution/helloWorld-solution.spec.js b/...orld/solution/helloWorld-solution.spec.js → ...orld/solution/helloWorld-solution.spec.js
diff --git a/foundations/02_addNumbers/README.md → ..._and_conditionals/02_addNumbers/README.md b/foundations/02_addNumbers/README.md → ..._and_conditionals/02_addNumbers/README.md
diff --git a/foundations/02_addNumbers/addNumbers.js → ..._conditionals/02_addNumbers/addNumbers.js b/foundations/02_addNumbers/addNumbers.js → ..._conditionals/02_addNumbers/addNumbers.js
diff --git a/foundations/02_addNumbers/addNumbers.spec.js → ...itionals/02_addNumbers/addNumbers.spec.js b/foundations/02_addNumbers/addNumbers.spec.js → ...itionals/02_addNumbers/addNumbers.spec.js
diff --git a/...ddNumbers/solution/addNumbers-solution.js → ...ddNumbers/solution/addNumbers-solution.js b/...ddNumbers/solution/addNumbers-solution.js → ...ddNumbers/solution/addNumbers-solution.js
diff --git a/...bers/solution/addNumbers-solution.spec.js → ...bers/solution/addNumbers-solution.spec.js b/...bers/solution/addNumbers-solution.spec.js → ...bers/solution/addNumbers-solution.spec.js
diff --git a/foundations/03_numberChecker/README.md → ...d_conditionals/03_numberChecker/README.md b/foundations/03_numberChecker/README.md → ...d_conditionals/03_numberChecker/README.md
diff --git a/...dations/03_numberChecker/numberChecker.js → ...tionals/03_numberChecker/numberChecker.js b/...dations/03_numberChecker/numberChecker.js → ...tionals/03_numberChecker/numberChecker.js
diff --git a/...ns/03_numberChecker/numberChecker.spec.js → ...ls/03_numberChecker/numberChecker.spec.js b/...ns/03_numberChecker/numberChecker.spec.js → ...ls/03_numberChecker/numberChecker.spec.js
diff --git a/...hecker/solution/numberChecker-solution.js → ...hecker/solution/numberChecker-solution.js b/...hecker/solution/numberChecker-solution.js → ...hecker/solution/numberChecker-solution.js
diff --git a/...r/solution/numberChecker-solution.spec.js → ...r/solution/numberChecker-solution.spec.js b/...r/solution/numberChecker-solution.spec.js → ...r/solution/numberChecker-solution.spec.js
diff --git a/foundations/04_mathEquations/README.md → ...d_conditionals/04_mathEquations/README.md b/foundations/04_mathEquations/README.md → ...d_conditionals/04_mathEquations/README.md
diff --git a/...dations/04_mathEquations/mathEquations.js → ...tionals/04_mathEquations/mathEquations.js b/...dations/04_mathEquations/mathEquations.js → ...tionals/04_mathEquations/mathEquations.js
diff --git a/...ns/04_mathEquations/mathEquations.spec.js → ...ls/04_mathEquations/mathEquations.spec.js b/...ns/04_mathEquations/mathEquations.spec.js → ...ls/04_mathEquations/mathEquations.spec.js
diff --git a/...ations/solution/mathEquations-solution.js → ...ations/solution/mathEquations-solution.js b/...ations/solution/mathEquations-solution.js → ...ations/solution/mathEquations-solution.js
diff --git a/...s/solution/mathEquations-solution.spec.js → ...s/solution/mathEquations-solution.spec.js b/...s/solution/mathEquations-solution.spec.js → ...s/solution/mathEquations-solution.spec.js
diff --git a/foundations/05_joinStrings/README.md → ...and_conditionals/05_joinStrings/README.md b/foundations/05_joinStrings/README.md → ...and_conditionals/05_joinStrings/README.md
diff --git a/...ons/05_joinStrings/joinStrings-example.js → ...als/05_joinStrings/joinStrings-example.js b/...ons/05_joinStrings/joinStrings-example.js → ...als/05_joinStrings/joinStrings-example.js
diff --git a/...5_joinStrings/joinStrings-example.spec.js → ...5_joinStrings/joinStrings-example.spec.js b/...5_joinStrings/joinStrings-example.spec.js → ...5_joinStrings/joinStrings-example.spec.js
diff --git a/foundations/05_joinStrings/joinStrings.js → ...onditionals/05_joinStrings/joinStrings.js b/foundations/05_joinStrings/joinStrings.js → ...onditionals/05_joinStrings/joinStrings.js
diff --git a/...ations/05_joinStrings/joinStrings.spec.js → ...ionals/05_joinStrings/joinStrings.spec.js b/...ations/05_joinStrings/joinStrings.spec.js → ...ionals/05_joinStrings/joinStrings.spec.js
diff --git a/...nStrings/solution/joinStrings-solution.js → ...nStrings/solution/joinStrings-solution.js b/...nStrings/solution/joinStrings-solution.js → ...nStrings/solution/joinStrings-solution.js
diff --git a/...ngs/solution/joinStrings-solution.spec.js → ...ngs/solution/joinStrings-solution.spec.js b/...ngs/solution/joinStrings-solution.spec.js → ...ngs/solution/joinStrings-solution.spec.js
diff --git a/foundations/06_repeatString/README.md → ...oops_and_arrays/01_repeatString/README.md b/foundations/06_repeatString/README.md → ...oops_and_arrays/01_repeatString/README.md
@@ -1,4 +1,4 @@
-# Exercise 06 - repeatString
+# Exercise 01 - repeatString
 
 Write a function that simply repeats the string a given number of times:
 

diff --git a/foundations/06_repeatString/repeatString.js → ...nd_arrays/01_repeatString/repeatString.js b/foundations/06_repeatString/repeatString.js → ...nd_arrays/01_repeatString/repeatString.js
diff --git a/...ions/06_repeatString/repeatString.spec.js → ...rays/01_repeatString/repeatString.spec.js b/...ions/06_repeatString/repeatString.spec.js → ...rays/01_repeatString/repeatString.spec.js
diff --git a/...tString/solution/repeatString-solution.js → ...tString/solution/repeatString-solution.js b/...tString/solution/repeatString-solution.js → ...tString/solution/repeatString-solution.js
diff --git a/...ng/solution/repeatString-solution.spec.js → ...ng/solution/repeatString-solution.spec.js b/...ng/solution/repeatString-solution.spec.js → ...ng/solution/repeatString-solution.spec.js
diff --git a/foundations/07_reverseString/README.md → ...ops_and_arrays/02_reverseString/README.md b/foundations/07_reverseString/README.md → ...ops_and_arrays/02_reverseString/README.md
@@ -1,4 +1,4 @@
-# Exercise 07 - Reverse a String
+# Exercise 02 - Reverse a String
 
 Pretty simple, write a function called `reverseString` that returns its input, reversed!
 

diff --git a/...dations/07_reverseString/reverseString.js → ..._arrays/02_reverseString/reverseString.js b/...dations/07_reverseString/reverseString.js → ..._arrays/02_reverseString/reverseString.js
diff --git a/...ns/07_reverseString/reverseString.spec.js → ...ys/02_reverseString/reverseString.spec.js b/...ns/07_reverseString/reverseString.spec.js → ...ys/02_reverseString/reverseString.spec.js
diff --git a/...String/solution/reverseString-solution.js → ...String/solution/reverseString-solution.js b/...String/solution/reverseString-solution.js → ...String/solution/reverseString-solution.js
diff --git a/...g/solution/reverseString-solution.spec.js → ...g/solution/reverseString-solution.spec.js b/...g/solution/reverseString-solution.spec.js → ...g/solution/reverseString-solution.spec.js
diff --git a/foundations/08_removeFromArray/README.md → ...s_and_arrays/03_removeFromArray/README.md b/foundations/08_removeFromArray/README.md → ...s_and_arrays/03_removeFromArray/README.md
@@ -1,4 +1,4 @@
-# Exercise 08 - removeFromArray
+# Exercise 03 - removeFromArray
 
 Implement a function that takes an array and some other arguments then removes the other arguments from that array, and returns the resulting array:
 

diff --git a/...ons/08_removeFromArray/removeFromArray.js → ...ays/03_removeFromArray/removeFromArray.js b/...ons/08_removeFromArray/removeFromArray.js → ...ays/03_removeFromArray/removeFromArray.js
diff --git a/...8_removeFromArray/removeFromArray.spec.js → ...3_removeFromArray/removeFromArray.spec.js b/...8_removeFromArray/removeFromArray.spec.js → ...3_removeFromArray/removeFromArray.spec.js
diff --git a/...rray/solution/removeFromArray-solution.js → ...rray/solution/removeFromArray-solution.js b/...rray/solution/removeFromArray-solution.js → ...rray/solution/removeFromArray-solution.js
diff --git a/...solution/removeFromArray-solution.spec.js → ...solution/removeFromArray-solution.spec.js b/...solution/removeFromArray-solution.spec.js → ...solution/removeFromArray-solution.spec.js
diff --git a/foundations/09_sumAll/README.md → ...ions/loops_and_arrays/04_sumAll/README.md b/foundations/09_sumAll/README.md → ...ions/loops_and_arrays/04_sumAll/README.md
@@ -1,4 +1,4 @@
-# Exercise 09 - sumAll
+# Exercise 04 - sumAll
 
 Implement a function that takes 2 positive integers and returns the sum of every integer between (and including) them:
 

diff --git a/...ons/09_sumAll/solution/sumAll-solution.js → ...ays/04_sumAll/solution/sumAll-solution.js b/...ons/09_sumAll/solution/sumAll-solution.js → ...ays/04_sumAll/solution/sumAll-solution.js
diff --git a/...9_sumAll/solution/sumAll-solution.spec.js → ...4_sumAll/solution/sumAll-solution.spec.js b/...9_sumAll/solution/sumAll-solution.spec.js → ...4_sumAll/solution/sumAll-solution.spec.js
diff --git a/foundations/09_sumAll/sumAll.js → ...ions/loops_and_arrays/04_sumAll/sumAll.js b/foundations/09_sumAll/sumAll.js → ...ions/loops_and_arrays/04_sumAll/sumAll.js
diff --git a/foundations/09_sumAll/sumAll.spec.js → ...loops_and_arrays/04_sumAll/sumAll.spec.js b/foundations/09_sumAll/sumAll.spec.js → ...loops_and_arrays/04_sumAll/sumAll.spec.js
diff --git a/foundations/10_leapYears/README.md → ...s/loops_and_arrays/05_leapYears/README.md b/foundations/10_leapYears/README.md → ...s/loops_and_arrays/05_leapYears/README.md
@@ -1,4 +1,4 @@
-# Exercise 10 - leapYears
+# Exercise 05 - leapYears
 
 Create a function that determines whether or not a given year is a leap year. Leap years are determined by the following rules:
 

diff --git a/foundations/10_leapYears/leapYears.js → ...oops_and_arrays/05_leapYears/leapYears.js b/foundations/10_leapYears/leapYears.js → ...oops_and_arrays/05_leapYears/leapYears.js
diff --git a/foundations/10_leapYears/leapYears.spec.js → ...and_arrays/05_leapYears/leapYears.spec.js b/foundations/10_leapYears/leapYears.spec.js → ...and_arrays/05_leapYears/leapYears.spec.js
diff --git a/..._leapYears/solution/leapYears-solution.js → ..._leapYears/solution/leapYears-solution.js b/..._leapYears/solution/leapYears-solution.js → ..._leapYears/solution/leapYears-solution.js
diff --git a/...Years/solution/leapYears-solution.spec.js → ...Years/solution/leapYears-solution.spec.js b/...Years/solution/leapYears-solution.spec.js → ...Years/solution/leapYears-solution.spec.js
diff --git a/foundations/11_tempConversion/README.md → ...ps_and_arrays/06_tempConversion/README.md b/foundations/11_tempConversion/README.md → ...ps_and_arrays/06_tempConversion/README.md
@@ -1,4 +1,4 @@
-# Exercise 11 - tempConversion
+# Exercise 06 - tempConversion
 
 Write two functions that convert temperatures from Fahrenheit to Celsius, and vice versa:
 

diff --git a/...rsion/solution/tempConversion-solution.js → ...rsion/solution/tempConversion-solution.js b/...rsion/solution/tempConversion-solution.js → ...rsion/solution/tempConversion-solution.js
diff --git a/.../solution/tempConversion-solution.spec.js → .../solution/tempConversion-solution.spec.js b/.../solution/tempConversion-solution.spec.js → .../solution/tempConversion-solution.spec.js
diff --git a/...tions/11_tempConversion/tempConversion.js → ...rrays/06_tempConversion/tempConversion.js b/...tions/11_tempConversion/tempConversion.js → ...rrays/06_tempConversion/tempConversion.js
diff --git a/.../11_tempConversion/tempConversion.spec.js → .../06_tempConversion/tempConversion.spec.js b/.../11_tempConversion/tempConversion.spec.js → .../06_tempConversion/tempConversion.spec.js
diff --git a/foundations/12_calculator/README.md → ...ons/object_basics/01_calculator/README.md b/foundations/12_calculator/README.md → ...ons/object_basics/01_calculator/README.md
@@ -1,4 +1,4 @@
-# Exercise 12 - Calculator
+# Exercise 01 - Calculator
 
 The goal for this exercise is to create a calculator that does the following:
 

diff --git a/foundations/12_calculator/calculator.js → ...object_basics/01_calculator/calculator.js b/foundations/12_calculator/calculator.js → ...object_basics/01_calculator/calculator.js
diff --git a/foundations/12_calculator/calculator.spec.js → ...t_basics/01_calculator/calculator.spec.js b/foundations/12_calculator/calculator.spec.js → ...t_basics/01_calculator/calculator.spec.js
diff --git a/...alculator/solution/calculator-solution.js → ...alculator/solution/calculator-solution.js b/...alculator/solution/calculator-solution.js → ...alculator/solution/calculator-solution.js
diff --git a/...ator/solution/calculator-solution.spec.js → ...ator/solution/calculator-solution.spec.js b/...ator/solution/calculator-solution.spec.js → ...ator/solution/calculator-solution.spec.js
diff --git a/foundations/13_palindromes/README.md → ...ns/object_basics/02_palindromes/README.md b/foundations/13_palindromes/README.md → ...ns/object_basics/02_palindromes/README.md
@@ -1,4 +1,4 @@
-# Exercise 13 - Palindromes
+# Exercise 02 - Palindromes
 
 Write a function that determines whether or not a given string is a palindrome.
 

diff --git a/foundations/13_palindromes/palindromes.js → ...ject_basics/02_palindromes/palindromes.js b/foundations/13_palindromes/palindromes.js → ...ject_basics/02_palindromes/palindromes.js
diff --git a/...ations/13_palindromes/palindromes.spec.js → ...basics/02_palindromes/palindromes.spec.js b/...ations/13_palindromes/palindromes.spec.js → ...basics/02_palindromes/palindromes.spec.js
diff --git a/...indromes/solution/palindromes-solution.js → ...indromes/solution/palindromes-solution.js b/...indromes/solution/palindromes-solution.js → ...indromes/solution/palindromes-solution.js
diff --git a/...mes/solution/palindromes-solution.spec.js → ...mes/solution/palindromes-solution.spec.js b/...mes/solution/palindromes-solution.spec.js → ...mes/solution/palindromes-solution.spec.js
diff --git a/foundations/14_fibonacci/README.md → ...ions/object_basics/03_fibonacci/README.md b/foundations/14_fibonacci/README.md → ...ions/object_basics/03_fibonacci/README.md
@@ -1,4 +1,4 @@
-# Exercise 14 - Fibonacci
+# Exercise 03 - Fibonacci
 
 Create a function that returns a specific member of the Fibonacci sequence (series of numbers in which each number is the sum of the two preceding numbers). To learn more about Fibonacci sequences, go to: https://en.wikipedia.org/wiki/Fibonacci_sequence
 

diff --git a/foundations/14_fibonacci/fibonacci.js → ...s/object_basics/03_fibonacci/fibonacci.js b/foundations/14_fibonacci/fibonacci.js → ...s/object_basics/03_fibonacci/fibonacci.js
diff --git a/foundations/14_fibonacci/fibonacci.spec.js → ...ect_basics/03_fibonacci/fibonacci.spec.js b/foundations/14_fibonacci/fibonacci.spec.js → ...ect_basics/03_fibonacci/fibonacci.spec.js
diff --git a/..._fibonacci/solution/fibonacci-solution.js → ..._fibonacci/solution/fibonacci-solution.js b/..._fibonacci/solution/fibonacci-solution.js → ..._fibonacci/solution/fibonacci-solution.js
diff --git a/...nacci/solution/fibonacci-solution.spec.js → ...nacci/solution/fibonacci-solution.spec.js b/...nacci/solution/fibonacci-solution.spec.js → ...nacci/solution/fibonacci-solution.spec.js
diff --git a/foundations/15_getTheTitles/README.md → ...s/object_basics/04_getTheTitles/README.md b/foundations/15_getTheTitles/README.md → ...s/object_basics/04_getTheTitles/README.md
@@ -1,4 +1,4 @@
-# Exercise 15 - Get the Titles!
+# Exercise 04 - Get the Titles!
 
 You are given an array of objects that represent books with an author and a title that looks like this:
 

diff --git a/foundations/15_getTheTitles/getTheTitles.js → ...ct_basics/04_getTheTitles/getTheTitles.js b/foundations/15_getTheTitles/getTheTitles.js → ...ct_basics/04_getTheTitles/getTheTitles.js
diff --git a/...ions/15_getTheTitles/getTheTitles.spec.js → ...sics/04_getTheTitles/getTheTitles.spec.js b/...ions/15_getTheTitles/getTheTitles.spec.js → ...sics/04_getTheTitles/getTheTitles.spec.js
diff --git a/...eTitles/solution/getTheTitles-solution.js → ...eTitles/solution/getTheTitles-solution.js b/...eTitles/solution/getTheTitles-solution.js → ...eTitles/solution/getTheTitles-solution.js
diff --git a/...es/solution/getTheTitles-solution.spec.js → ...es/solution/getTheTitles-solution.spec.js b/...es/solution/getTheTitles-solution.spec.js → ...es/solution/getTheTitles-solution.spec.js
diff --git a/foundations/16_findTheOldest/README.md → .../object_basics/05_findTheOldest/README.md b/foundations/16_findTheOldest/README.md → .../object_basics/05_findTheOldest/README.md
@@ -1,4 +1,4 @@
-# Exercise 16 - Find the Oldest
+# Exercise 05 - Find the Oldest
 
 Given an array of objects representing people with a birth and death year, return the oldest person.
 

diff --git a/...dations/16_findTheOldest/findTheOldest.js → ..._basics/05_findTheOldest/findTheOldest.js b/...dations/16_findTheOldest/findTheOldest.js → ..._basics/05_findTheOldest/findTheOldest.js
diff --git a/...ns/16_findTheOldest/findTheOldest.spec.js → ...cs/05_findTheOldest/findTheOldest.spec.js b/...ns/16_findTheOldest/findTheOldest.spec.js → ...cs/05_findTheOldest/findTheOldest.spec.js
diff --git a/...Oldest/solution/findTheOldest-solution.js → ...Oldest/solution/findTheOldest-solution.js b/...Oldest/solution/findTheOldest-solution.js → ...Oldest/solution/findTheOldest-solution.js
diff --git a/...t/solution/findTheOldest-solution.spec.js → ...t/solution/findTheOldest-solution.spec.js b/...t/solution/findTheOldest-solution.spec.js → ...t/solution/findTheOldest-solution.spec.js