update traits section

src/traits/index.md

@@ -1,5 +1,5 @@
 # Traits
-Traits can be used to represent common behaviors. As a result of the implementation of a trait by one or more structures that exhibit common behavior, the trait it applies to becomes usable wherever it is used. A trait can only contain functions. Every function declaration is automatically public and marked as `pub`. A trait can be `nil`
+Traits can be used to represent common behaviors. As a result of the implementation of a trait by one or more structures that exhibit common behavior, the trait it applies to becomes usable wherever it is used. A trait can only contain functions. A trait can be `nil`
 
 ## Define a Trait
 Functions in a trait should only exist as prototypes (declaration of a trait, not a definition).
@@ -13,5 +13,17 @@ trait Person {
 ```
 All constructs that implement the trait above, must have the methods `name() str` and `age() u8`.
 
+## Access Modifiers
+
+Traits supports access modifiers for definitions. And access modifier of relevant define, should implemented as same.
+
+For example:
+```
+trait Person {
+    pub fn name(): str
+    pub fn age(): u8
+}
+```
+
 ## Comparing Traits
 During a comparison of traits: equal traits return true if two traits use the same allocation (both have the same pointer address), false if not.