Update string.h.md

1 files changed, 31 insertions, 1 deletions

diff --git a/doc/api/mruby/string.h.md b/doc/api/mruby/string.h.md
index e2a10c2cf..428a3ca40 100644
--- a/doc/api/mruby/string.h.md
+++ b/doc/api/mruby/string.h.md
@@ -10,6 +10,36 @@ Adds to strings together.
 Converts pointer into a Ruby string.

 ### mrb_obj_as_string

 ```C

-   mrb_obj_as_string(mrb_state *mrb, mrb_value obj);

+   mrb_value mrb_obj_as_string(mrb_state *mrb, mrb_value obj);

 ```

 Returns an object as a Ruby string.

+### mrb_str_resize

+```C

+   mrb_value mrb_str_resize(mrb_state *mrb, mrb_value str, mrb_int len);

+```

+Resizes the string's length.

+### mrb_str_substr

+```C

+   mrb_value mrb_str_substr(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len);

+```

+Returns a sub string.

+### mrb_string_type

+```C

+   mrb_value mrb_string_type(mrb_state *mrb, mrb_value str);

+```

+Returns a Ruby string type.

+### mrb_str_new_cstr

+```C

+   const char *mrb_string_value_cstr(mrb_state *mrb, mrb_value *ptr);

+```

+Returns a Ruby string as a C string.

+### mrb_str_dup

+```C

+   mrb_value mrb_str_dup(mrb_state *mrb, mrb_value str);

+```

+Duplicates a string object.

+### mrb_str_intern

+```C

+   mrb_value mrb_str_intern(mrb_state *mrb, mrb_value self);

+```

+Returns a symbol from a passed in string.