2 files changed, 24 insertions, 0 deletions
diff --git a/doc/string/bytesize.rdoc b/doc/string/bytesize.rdoc
new file mode 100644
index 0000000000..b0567ff67b
--- /dev/null
+++ b/doc/string/bytesize.rdoc
@@ -0,0 +1,11 @@
+Returns the count of bytes (not characters) in +self+:
+
+  'foo'.bytesize        # => 3
+  'тест'.bytesize       # => 8
+  'こんにちは'.bytesize   # => 15
+
+Contrast with String#length:
+
+  'foo'.length       # => 3
+  'тест'.length      # => 4
+  'こんにちは'.length  # => 5
diff --git a/doc/string/length.rdoc b/doc/string/length.rdoc
new file mode 100644
index 0000000000..0a7e17f7dc
--- /dev/null
+++ b/doc/string/length.rdoc
@@ -0,0 +1,13 @@
+Returns the count of characters (not bytes) in +self+:
+
+  'foo'.length        # => 3
+  'тест'.length       # => 4
+  'こんにちは'.length   # => 5
+
+Contrast with String#bytesize:
+
+  'foo'.bytesize        # => 3
+  'тест'.bytesize       # => 8
+  'こんにちは'.bytesize   # => 15
+
+String#size is an alias for String#length.