Update snippet descriptions

snippets/isAlphaNumeric.md

@@ -5,7 +5,7 @@ tags: string,regexp,beginner
 
 Checks if a string contains only alphanumeric characters.
 
-- Use `RegExp.prototype.test()` to check if input string matches against alphanumeric regex pattern.
+- Use `RegExp.prototype.test()` to check if the input string matches against the alphanumeric regexp pattern.
 
 ```js
 const isAlphaNumeric = str => /^[a-z0-9]+$/gi.test(str);