Improved pangram algorithm using regular expressions

String/CheckPangram.js

@@ -1,22 +1,23 @@
-/*
- Pangram is a sentence that contains all the letters in the alphabet
- https://en.wikipedia.org/wiki/Pangram
+/**
+ * @function checkPangram
+ * @description - Pangram is a sentence that contains all the letters in the alphabet https://en.wikipedia.org/wiki/Pangram
+ * @param {string} string
+ * @returns {boolean}
  */
-
 const checkPangram = (string) => {
  if (typeof string !== 'string') {
  throw new TypeError('The given value is not a string')
  }
 
- const frequency = new Set()
-
- for (const letter of string.toLowerCase()) {
-  if (letter >= 'a' && letter <= 'z') {
-  frequency.add(letter)
-  }
- }
-
- return frequency.size === 26
+ /**
+ * match all 26 alphabets using regex, with the help of:
+  * Capturing Group
+ * Character set
+ * Negative lookahead
+ * Dot & star
+  * Numeric reference
+ */
+ return string.match(/([a-z])(?!.*\1)/gi).length === 26
 }
 
 export { checkPangram }