add UpperCaseConversion method

Conversions/UpperCaseConversion.js

@@ -0,0 +1,35 @@
+/*
+    Explanation :- a user gives a String (it can be incomplete lower or
+        partial lower) and then the program would convert it into a
+        complete(all characters in upper case) upper case string. The
+        logic we have used in the following program is: All the lower case
+        characters (a-z) has ASCII value ranging from 97 to 122 and their
+        corresponding upper case characters (A-Z) have ASCII values 32
+        lesser than them. For example ‘a‘ has an ASCII value of 97
+        and ‘A‘ has an ASCII value of 65 (97 - 32). The same applies to other
+        characters.
+*/
+
+/**
+ * UpperCaseConversion takes any case-style string and converts it to the upper case-style string.
+ * @param {String} inputString any case style string
+ * @returns {String} upper case string
+ */
+const UpperCaseConversion = (inputString) => {
+  // Take a string and split it into characters.
+  const newString = inputString.split('').map(char => {
+    // Get a character code by the use charCodeAt method.
+    const presentCharCode = char.charCodeAt()
+    // If the character code lies between 97 to 122 it means they are in the lower case so convert it.
+    if (presentCharCode >= 97 && presentCharCode <= 122) {
+      // Convert the case by use of the above explanation.
+      return String.fromCharCode(presentCharCode - 32)
+    }
+    // Else return the characters without any modification.
+    return char
+  })
+  // After modification, with the help of the join method, join all the characters and return them.
+  return newString.join('')
+}
+
+module.exports = UpperCaseConversion