Create abs.js

This script calculates absolute value.

maths/abs.js

@@ -0,0 +1,26 @@
+/*
+    author: PatOnTheBack
+    license: GPL-3.0 or later
+
+    Modified from:
+        https://github.com/TheAlgorithms/Python/blob/master/maths/abs.py
+
+    This script will find the absolute value of a number.
+
+    More about absolute values:
+        https://en.wikipedia.org/wiki/Absolute_value
+*/
+
+function abs_val(num) {
+    // Find absolute value of `num`.
+    "use strict";
+    if (num < 0) {
+        return -num
+    }
+    // Executes if condition is not met.
+    return num
+}
+
+// Run `abs` function to find absolute value of two numbers.
+console.log("The absolute value of -34 is " + abs_val(-34));
+console.log("The absolute value of 34 is " + abs_val(34));