algorithm : Added a Maths' Function as Abs.ts #10

Author: Owais28

.gitignore

@@ -1,7 +1,6 @@
 # dependencies
 /node_modules
 /temp
-/Maths
 # misc
 .DS_Store
 .env.local

Maths/Abs.ts

@@ -0,0 +1,18 @@
+/**
+ * A function to get absolute value of a given number
+ * @param {number} num - The input integer
+ * @return {number} Absolute vlaue of `num`
+ * @example abs(-10) => 10 | abs(50) => 50 | abs(0) => 0
+ * @see https://en.wikipedia.org/wiki/Absolute_value
+ * @author Owais28 <https://github.com/Owais28>
+ */
+
+export const abs = (num: number ): number => {
+  const validNumber : number = +num; // converted to number, also can use - Number(num)
+
+  if (Number.isNaN(validNumber)) {
+    throw new TypeError("Argument is NaN - Not a Number");
+  }
+
+  return validNumber < 0 ? -validNumber : validNumber; // if number is less then zero mean negative then it converted to positive. i.e -> n = -2 = -(-2) = 2
+};

Maths/test/Abs.test.ts

@@ -0,0 +1,25 @@
+import { abs } from '../Abs'
+
+describe('Testing abs function', () => {
+  
+
+  it('should return an absolute value of a negative number', () => {
+    const absOfNegativeNumber = abs(-34)
+    expect(absOfNegativeNumber).toBe(34)
+  })
+
+  it('should return an absolute value of a positive number', () => {
+    const absOfPositiveNumber = abs(50)
+    expect(absOfPositiveNumber).toBe(50)
+  })
+
+  it('should return an absolute value of a zero number', () => {
+    const absOfPositiveNumber = abs(0)
+    expect(absOfPositiveNumber).toBe(0)
+  })
+
+  it('should return an absolute value of any floating number', () => {
+    const absOfPositiveNumber = abs(-20.2034)
+    expect(absOfPositiveNumber).toBe(20.2034)
+  })
+})