Fixes #124

Author: chenglou

pages/docs/manual/latest/primitive-types.mdx

@@ -118,7 +118,7 @@ var firstLetterOfAlphabet = /* "a" */97;
 
 **Note**: Char doesn't support Unicode or UTF-8 and is therefore not recommended.
 
-To convert a String to a Char, use `"a".[0]`. To convert a Char to a String, use `String.make(1, 'a')`.
+To convert a String to a Char, use `String.get("a", 0)`. To convert a Char to a String, use `String.make(1, 'a')`.
 
 ## Regular Expression