es 6

index.js

@@ -4,18 +4,18 @@
  * Mean, Median, Mode
  */
 
-var mean = numbers => {
+let mean = numbers => {
     if (!Array.isArray(numbers)) {
         return null;
     }
     return numbers.reduce((pv, cv) => pv + cv, 0) / numbers.length;
 }
 
-var median = numbers => {
+let median = numbers => {
     if (!Array.isArray(numbers)) {
         return null;
     }
-    var median = 0, numsLen = numbers.length;
+    let median = 0, numsLen = numbers.length;
     numbers.sort();
 
     if (numbers.length % 2 == 0) {
@@ -26,19 +26,19 @@ var median = numbers => {
     return median;
 }
 
-var mode = numbers => {
+let mode = numbers => {
     if (!Array.isArray(numbers)) {
         return null;
     }
-    var modes = [], count = [], i, number, maxIndex = 0;
-    for (i = 0; i < numbers.length; i += 1) {
-        number = numbers[i];
-        count[number] = (count[number] || 0) + 1;
-        if (count[number] > maxIndex) {
-            maxIndex = count[number];
-        }
+    let modes = [], count = [], maxIndex = 0;
+
+    for (let value of numbers) {
+        count[value] = (count[value] || 0) + 1;
+        if (count[value] > maxIndex)
+            maxIndex = count[value];
     }
-    for (i in count) {
+
+    for (let i of numbers) {
         if (count.hasOwnProperty(i)) {
             if (count[i] === maxIndex) {
                 modes.push(Number(i));
@@ -49,25 +49,25 @@ var mode = numbers => {
     return modes;
 }
 
-var standardDeviation = numbers => {
+let standardDeviation = numbers => {
     if (!Array.isArray(numbers)) {
         return null;
     }
 
     return Math.sqrt(variance(numbers));
 }
 
-var variance = numbers => {
+let variance = numbers => {
     if (!Array.isArray(numbers)) {
         return null;
     }
-    var initialMean = mean(numbers);
-    var varianceNumbersArray = [], i;
+    let initialMean = mean(numbers);
+    let varianceNumbersArray = [], i;
     for(i = 0; i < numbers.length; i += 1) {
-        var varianceNumber = numbers[i] - initialMean;
+        let varianceNumber = numbers[i] - initialMean;
         varianceNumbersArray.push(varianceNumber * varianceNumber);
     }
-    var variance = mean(varianceNumbersArray);
+    let variance = mean(varianceNumbersArray);
 
     return variance;
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "math-stats",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "description": "Mean, Median, Mode",
   "main": "index.js",
   "scripts": {

test/test.js

@@ -4,27 +4,27 @@ var expect = require('chai').expect;
 var stats = require('../index');
 
 describe('#stats', function() {
-        it('should return 2', function() {
+        it('Median', function() {
                 var result = stats.median([1,2,3]);
                 expect(result).to.equal(2);
         });
-        it('should throw not an array error', function() {
+        it('Not an array error', function() {
                 var result = stats.median(1);
                 expect(result).to.equal(null);
         });
-        it('should return 1', function() {
+        it('Mode', function() {
                 var result = stats.mode([1, 2, 1, 3]);
                 expect(result[0]).to.equal(1);
         });
-        it('should return 3', function() {
+        it('Mean', function() {
                 var result = stats.mean([1, 2, 3]);
                 expect(result).to.equal(2);
         });
-        it('should return 0.816', function() {
+        it('Standard Deviation', function() {
                 var result = stats.standardDeviation([1, 2, 3]);
                 expect(result).to.equal(0.816496580927726);
         })
-        it('should return 0.666', function() {
+        it('Variance', function() {
                 var result = stats.variance([1, 2, 3]);
                 expect(result).to.equal(0.6666666666666666);
         })