diff --git a/SwiftStudy.playground/Pages/04 函数.xcplaygroundpage/Contents.swift b/SwiftStudy.playground/Pages/04 函数.xcplaygroundpage/Contents.swift
new file mode 100644
index 0000000..586d5d7
--- /dev/null
+++ b/SwiftStudy.playground/Pages/04 函数.xcplaygroundpage/Contents.swift	
@@ -0,0 +1,48 @@
+//: [Previous](@previous)
+
+//: ## 函数
+/*:
+    函数的定义:
+    func 函数名称 (形参: 形参类型, ...) -> 函数返回值 {}
+    - 形参默认是let，也只能是let
+ */
+func sum(v1: Int, v2: Int) -> Int {
+    return v1 + v2
+}
+
+
+//: ### 无返回值的函数
+func sayHello() -> Void {}
+func sayHello1() -> () {}
+func sayHello2() {}
+
+//: ### 隐式返回值
+// 如果整个函数体是一个单一表达式，那么函数会隐式返回这个表达式
+func sum0(v1: Int, v2: Int) -> Int {
+    v1 + v2
+}
+
+//: ### 返回元组（实现多返回值）
+func caculate(v1: Int, v2: Int) -> (sum: Int, difference: Int, average: Int) {
+    let sum = v1 + v2
+    
+    return (sum, v1 - v2, sum >> 1)
+}
+
+let result = caculate(v1:20, v2:10)
+result.sum
+
+//: ### 函数文档注释
+/// 求和
+///
+///
+func addNumber(v1: Int, v2: Int) -> Int {
+    v1 + v2
+}
+
+addNumer(v1: 20, v2: 30);
+
+//: ###参数标签
+
+
+//: [Next](@next)
diff --git a/SwiftStudy.playground/contents.xcplayground b/SwiftStudy.playground/contents.xcplayground
index 9e18224..0b8b36b 100644
--- a/SwiftStudy.playground/contents.xcplayground
+++ b/SwiftStudy.playground/contents.xcplayground
@@ -4,5 +4,6 @@
         <page name='01 注释'/>
         <page name='02 数据类型'/>
         <page name='03 流程控制'/>
+        <page name='04 函数'/>
     </pages>
 </playground>
\ No newline at end of file
diff --git a/SwiftStudy.playground/playground.xcworkspace/xcuserdata/jiulinxiri.xcuserdatad/UserInterfaceState.xcuserstate b/SwiftStudy.playground/playground.xcworkspace/xcuserdata/jiulinxiri.xcuserdatad/UserInterfaceState.xcuserstate
index 6ee4b49..2d8133d 100644
Binary files a/SwiftStudy.playground/playground.xcworkspace/xcuserdata/jiulinxiri.xcuserdatad/UserInterfaceState.xcuserstate and b/SwiftStudy.playground/playground.xcworkspace/xcuserdata/jiulinxiri.xcuserdatad/UserInterfaceState.xcuserstate differ