Add Kilometers/Hour to Miles/Hour conversion and reverse

snippets/kphToMph.md

@@ -0,0 +1,14 @@
+### kphToMph
+
+Convert kilometers/hour to miles/hour.
+
+Multiply the constant of proportionality with the argument.
+
+```js
+const kphToMph = (kph) => 0.621371192 * kph;
+```
+
+```js
+kphToMph(10); //16.09344000614692
+kphToMph(345.4); //138.24264965280207
+```

snippets/mphToKph.md

@@ -0,0 +1,14 @@
+### mphToKph
+
+Convert miles/hour to kilometers/hour.
+
+Multiply the constant of proportionality with the argument.
+
+```js
+const mphToKph = (mph) => 1.6093440006146922 * mph;
+```
+
+```js
+mphToKph(10); //16.09344000614692
+mphToKph(85.9); //138.24264965280207
+```

tag_database

@@ -168,6 +168,7 @@ isWritableStream:node,type,intermediate
 join:array,intermediate
 JSONtoCSV:array,string,object,advanced
 JSONToFile:node,json,intermediate
+kphToMph:utility,beginner
 last:array,beginner
 lcm:math,recursion,beginner
 longestItem:array,string,utility,intermediate
@@ -190,6 +191,7 @@ minBy:math,array,function,beginner
 minDate:date,math,beginner
 minN:array,math,beginner
 mostPerformant:utility,function
+mphToKph:utility,beginner
 negate:function,beginner
 nest:object,intermediate
 nodeListToArray:browser,array,beginner

test/kphToMph/kphToMph.js

@@ -0,0 +1,2 @@
+const kphToMph = (kph) => 0.621371192 * kph;
+module.exports = kphToMph;

test/kphToMph/kphToMph.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const kphToMph = require('./kphToMph.js');
+
+test('kphToMph is a Function', () => {
+  expect(kphToMph).toBeInstanceOf(Function);
+});
+test('Returns mph from kph.', () => {
+  expect(kphToMph(10)).toBe(6.21371192);
+});
+test('Returns mph from kph.', () => {
+  expect(kphToMph(345.4)).toBe(214.62160971679998);
+});

test/mphToKph/mphToKph.js

@@ -0,0 +1,2 @@
+const mphToKph = (mph) => 1.6093440006146922 * mph;
+module.exports = mphToKph;

test/mphToKph/mphToKph.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const mphToKph = require('./mphToKph.js');
+
+test('mphToKph is a Function', () => {
+  expect(mphToKph).toBeInstanceOf(Function);
+});
+test('Returns kph from mph.', () => {
+  expect(mphToKph(10)).toBe(16.09344000614692);
+});
+test('Returns kph from mph.', () => {
+  expect(mphToKph(85.9)).toBe(138.24264965280207);
+});