Modify README

README.md

@@ -155,6 +155,15 @@ e = 5
 姓 = "黄"
 ```
 
+Note however, if you do not use the keyword `let`, you could not do multiple variable assignments.
+Below code is not correct：
+
+```swift
+//Error, multiple variable assignments must be use `let` keyword
+a, b, c = 1, "hello world", [1,2,3]
+```
+
+
 ### Reserved keywords
 
 Keywords are predefined, reserved identifiers that have special meanings to the compiler. They cannot be used as identifiers. Below is a list of reserved keywords
@@ -782,6 +791,26 @@ fn sub(x,y=2) {
 println(sub(10)) //output : 8
 ```
 
+Monkey do not support multiple return values, But there are many ways to do it.
+
+Below suggest a way of doing it:
+
+```swift
+fn div(x, y) {
+	if y == 0 {
+		return [nil, "y could not be zero"]
+	}
+	return [x/y, ""]
+}
+
+ret = div(10,5)
+if ret[1] != "" {
+	println(ret[1])
+} else {
+	println(ret[0])
+}
+```
+
 ## Pipe Operator
 
 The pipe operator, inspired by [Elixir](https://elixir-lang.org/).

README_cn.md

@@ -159,6 +159,13 @@ e = 5
 姓="黄"
 ```
 
+如果你不使用`let`来给变量赋值，那么你将不能使用多变量赋值。下面的语句是错误的：
+
+```swift
+//错误,多变量赋值必须使用let关键字
+a, b, c = 1, "hello world", [1,2,3]
+```
+
 ## 保留字
 
 下面列出了monkey语言的保留字：
@@ -765,6 +772,26 @@ fn sub(x,y=2) {
 println(sub(10)) //结果 : 8
 ```
 
+Monkey不支持多个返回值, 但有很多方法可以达到目的.
+
+下面是其中的一种实现方式:
+
+```swift
+fn div(x, y) {
+	if y == 0 {
+		return [nil, "y could not be zero"]
+	}
+	return [x/y, ""]
+}
+
+ret = div(10,5)
+if ret[1] != "" {
+	println(ret[1])
+} else {
+	println(ret[0])
+}
+```
+
 ## Pipe操作符
 
 `pipe`操作符来自[Elixir](https://elixir-lang.org/).