feat: Added difference function

Author: terkelg

README.md

@@ -74,6 +74,7 @@ https://unpkg.com/math-toolbox/dist/math-toolbox.umd.min.js
 | percent | Calculate percantage of value. |
 | isOdd | Returns true if the number given is odd. |
 | isEven | Returns true if the number given is even. |
+| difference | Returns the absolute difference between two values. |
 
 ## Plans
 See GitHub Wiki:

docs/index.html

@@ -283,6 +283,16 @@ <h3 class='mb0 no-anchor'></h3>
 
                 </li>
 
+                
+                <li><a
+                  href='#difference'
+                  class="">
+                  difference
+                  
+                </a>
+                
+                </li>
+              
             </ul>
           </div>
           <div class='mt1 h6 quiet'>
@@ -2288,6 +2298,79 @@ <h3 class='fl m0' id='percent'>
 
 
 
+</section>
+
+          
+        
+          
+            <section class='p2 mb2 clearfix bg-white minishadow'>
+
+  
+  <div class='clearfix'>
+    <h3 class='fl m0' id='difference'>
+      difference
+    </h3>
+    
+  </div>
+  
+
+  <p>The absolute difference between two values.</p>
+
+
+  <div class='pre p1 fill-light mt0'>difference(a: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a>, b: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a>): <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a></div>
+
+  
+
+  
+  
+  
+  
+  
+
+  
+    <div class='py1 quiet mt1 prose-big'>Parameters</div>
+    <div class='prose'>
+      
+        <div class='space-bottom0'>
+          <div>
+            <span class='code bold'>a</span> <code class='quiet'>(<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a>)</code> The first value to check.
+
+          </div>
+          
+        </div>
+      
+        <div class='space-bottom0'>
+          <div>
+            <span class='code bold'>b</span> <code class='quiet'>(<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a>)</code> The second value to check.
+
+          </div>
+          
+        </div>
+      
+    </div>
+  
+
+  
+
+  
+    
+      <div class='py1 quiet mt1 prose-big'>Returns</div>
+      <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number">number</a></code>:
+        The absolute difference between the two values.
+
+      
+    
+  
+
+  
+
+  
+
+  
+
+  
+
+  
 </section>
 
 

src/difference.js

@@ -0,0 +1,12 @@
+/**
+ * The absolute difference between two values.
+ *
+ * @param {number} a - The first value to check.
+ * @param {number} b - The second value to check.
+ * @return {number} The absolute difference between the two values.
+ */
+function difference (a, b) {
+  return Math.abs(a - b)
+}
+
+export { difference }

src/math-toolbox.js

@@ -24,4 +24,4 @@ export { average } from './average'
 export { isOdd } from './is-odd'
 export { isEven } from './is-even'
 export { percent } from './percent'
-// difference
+export { difference } from './difference'

test/difference.test.js

@@ -0,0 +1,7 @@
+import { difference } from '../src/math-toolbox'
+
+describe('Calculate absolute difference', () => {
+  it('', () => {
+    expect(difference(10, 20)).toBe(10)
+  })
+})