Added snippet for isAlphabetOnly

snippets/isAlphabetOnly.md

@@ -0,0 +1,18 @@
+---
+title: isAlphabetOnly
+tags: string,regexp,beginner
+---
+
+Checks if a string contains only alphabetic characters.
+- Use `RegExp.prototype.test()` to check if the input string matches against the alphabetic regexp pattern.
+
+
+```js
+const isAlphabetOnly = input => /^[a-zA-Z]*$/.test(input)
+```
+
+```js
+isAlphabetOnly('sampleInput'); // true
+isAlphabetOnly('this Will fail'); // false
+isAlphabetOnly('123'); // false
+```