Merge branch 'master' of github.com:learn-co-curriculum/javascript-ar…

…rays

README.md

@@ -31,7 +31,7 @@ But now what if we want to make a tomato sauce? Well, we already have garlic and
 
 This is an admittedly contrived example, but it goes to show that we can't just put everything in a variable and hope to remember what order things should go in. It also shows that sometimes it would be helpful to be able to group like items together.
 
-In JavaScript, we can group like items in an object (well, everything in JavaScript is an object — but more on that some other time) called an _array_. And array is an ordered list of items (called "elements" of the array) separated by commas.
+In JavaScript, we can group like items in an object (well, everything in JavaScript is an object — but more on that some other time) called an _array_. An array is an ordered list of items (called "elements" of the array) separated by commas.
 
 Arrays look like this: `[1, 2, 3]`.
 
@@ -58,7 +58,7 @@ var tomatoSauceIngredients = [
 
 ## Creation
 
-JavaScript arrays can contain any types of values and they can be of mixed types. You can create arrays in two different ways, the most common of which is to list values in a pair of square brackets. These are called **array literals**.
+JavaScript arrays can contain all types of values and they can be of mixed types. You can create arrays in two different ways, the most common of which is to list values in a pair of square brackets. These are called **array literals**.
 
 ```javascript
 var myArray = [element0, element1, ..., elementN];

test/arrays-test.js

@@ -26,7 +26,7 @@ describe('arrays', () => {
 
       addElementToBeginningOfArray(array, 'foo')
 
-      expect(array).to.eql(array)
+      expect(array).to.eql([1])
     })
   })
 
@@ -77,13 +77,37 @@ describe('arrays', () => {
       expect(accessElementInArray([1, 2, 3], 2)).to.equal(3)
     })
   })
+
+  describe('destructivelyRemoveElementFromBeginningOfArray(array)', ()=>{
+    it('returns the `array` with the first element removed', () => {
+      expect(destructivelyRemoveElementFromBeginningOfArray([1, 2, 3])).to.eql([2, 3])
+    })
+
+    it('did not make a copy of the array when removing the first element', ()=>{
+      const array = [1, 2, 3];
+      destructivelyRemoveElementFromBeginningOfArray(array);
+      expect(array).to.eql([2, 3]);
+    })
+  })
 
   describe('removeElementFromBeginningOfArray(array)', () => {
     it('removes the first element from the `array`', () => {
       expect(removeElementFromBeginningOfArray([1, 2, 3])).to.eql([2, 3])
     })
   })
 
+  describe('destructivelyRemoveElementFromEndOfArray(array)', () => {
+    it('returns the `array` with the last element removed', () => {
+      expect(destructivelyRemoveElementFromEndOfArray([1, 2, 3])).to.eql([1, 2])
+    })
+
+    it('did not make a copy of the array when removing the last element', ()=>{
+      const array = [1, 2, 3];
+      destructivelyRemoveElementFromEndOfArray(array);
+      expect(array).to.eql([1, 2]);
+    })
+  })
+
   describe('removeElementFromEndOfArray(array)', () => {
     it('removes the last element from the `array`', () => {
       expect(removeElementFromEndOfArray([1, 2, 3])).to.eql([1, 2])