Added AbsoluteValue and its associated tests (#31)

Author: orangegrove1955

Maths/AbsoluteValue.ts

@@ -0,0 +1,16 @@
+/**
+ * @function AbsoluteValue
+ * @description Calculate the absolute value of an input number.
+ * @param {number} number - a numeric input value
+ * @return {number} - Absolute number of input number
+ * @see https://en.wikipedia.org/wiki/Absolute_value
+ * @example AbsoluteValue(-10) = 10
+ * @example AbsoluteValue(50) = 50
+ * @example AbsoluteValue(0) = 0
+ */
+
+export const AbsoluteValue = (number: number): number => {
+  // if input number is less than 0, convert it to positive via double negation
+  // e.g. if n = -2, then return -(-2) = 2
+  return number < 0 ? -number : number;
+};

Maths/test/AbsoluteValue.test.ts

@@ -0,0 +1,28 @@
+import { AbsoluteValue } from "../AbsoluteValue";
+
+describe("AbsoluteValue", () => {
+  it("should return the absolute value of zero", () => {
+    const absoluteValueOfZero = AbsoluteValue(0);
+    expect(absoluteValueOfZero).toBe(0);
+  });
+
+  it("should return the absolute value of a negative integer", () => {
+    const absoluteValueOfNegativeInteger = AbsoluteValue(-34);
+    expect(absoluteValueOfNegativeInteger).toBe(34);
+  });
+
+  it("should return the absolute value of a positive integer", () => {
+    const absoluteValueOfPositiveInteger = AbsoluteValue(50);
+    expect(absoluteValueOfPositiveInteger).toBe(50);
+  });
+
+  it("should return the absolute value of a positive floating number", () => {
+    const absoluteValueOfPositiveFloating = AbsoluteValue(20.2034);
+    expect(absoluteValueOfPositiveFloating).toBe(20.2034);
+  });
+
+  it("should return the absolute value of a negative floating number", () => {
+    const absoluteValueOfNegativeFloating = AbsoluteValue(-20.2034);
+    expect(absoluteValueOfNegativeFloating).toBe(20.2034);
+  });
+});