added numberOfDigitsUsingLog method (TheAlgorithms#1364)

* added numberOfDigitsUsingLog method

* added JSDoc comment

---------

Co-authored-by: madhuredra <[email protected]>

Author: dev-madhurendra

Maths/NumberOfDigits.js

@@ -9,4 +9,14 @@
 
 const numberOfDigit = (n) => Math.abs(n).toString().length
 
-export { numberOfDigit }
+/**
+ * Returns the number of digits of a given integer.
+ *
+ * @param {number} n - The integer for which to count digits.
+ * @returns {number} The number of digits in the integer.
+ * @see https://math.stackexchange.com/questions/2145480/how-does-the-logarithm-returns-the-number-of-digits-of-a-number
+ * @author dev-madhurendra
+ */
+const numberOfDigitsUsingLog = (n) => n === 0 ? 1 : Math.floor(Math.log10(Math.abs(n))) + 1
+
+export { numberOfDigit, numberOfDigitsUsingLog }

Maths/test/NumberOfDigits.test.js

@@ -1,4 +1,4 @@
-import { numberOfDigit } from '../NumberOfDigits'
+import { numberOfDigit, numberOfDigitsUsingLog } from '../NumberOfDigits'
 
 describe('NumberOfDigits', () => {
   it('should return the correct number of digits for an integer', () => {
@@ -8,4 +8,13 @@ describe('NumberOfDigits', () => {
   it('should return the correct number of digits for a negative number', () => {
     expect(numberOfDigit(-2346243)).toBe(7)
   })
+
+  it.each([
+    [0, 1],
+    [123423232, 9],
+    [-123423232, 9],
+    [9999, 4]
+  ])('should return the correct number of digits in an integer', (value, expected) => {
+    expect(numberOfDigitsUsingLog(value)).toBe(expected)
+  })
 })