diff --git a/day02/src/com/inmind/Demo07.java b/day02/src/com/inmind/Demo07.java
new file mode 100644
index 0000000..e89539b
--- /dev/null
+++ b/day02/src/com/inmind/Demo07.java
@@ -0,0 +1,20 @@
+package com.inmind;
+/*
+8.运算符_算术运算符_字符串连接
++ 符号在遇到字符串的时候，表示连接、拼接的含义,得到一个更长的字符串
+ */
+public class Demo07 {
+    public static void main(String[] args) {
+        //定义了一个字符串
+        String str = "abc";
+        //定义了一个字符串
+        String str1 = "123";
+        System.out.println(str+str1);//abc123
+
+        //数字与字符串进行加法运算
+        System.out.println("abc"+123);//abc123
+        System.out.println(123+"abc"+123);//123abc123
+        System.out.println(1+2+"abc");//3abc
+        System.out.println(1+2+"abc"+1+2);//12abc12
+    }
+}