diff --git a/day03/src/com/inmind/Demo04_while.java b/day03/src/com/inmind/Demo04_while.java
new file mode 100644
index 0000000..71a8158
--- /dev/null
+++ b/day03/src/com/inmind/Demo04_while.java
@@ -0,0 +1,43 @@
+package com.inmind;
+/*
+while循环的格式和使用
+
+循环变量初始化①
+while(循环条件②){
+	循环体语句③
+	修改循环变量④
+}
+
+执行顺序：①②③④>②③④>②③④…②不满足为止
+*/
+public class Demo04_while {
+    public static void main(String[] args) {
+        //使用while的语法，计算出1~100的偶数累和
+    }
+
+
+    //while循环的语法学习
+    public static void whileMethod(String[] args) {
+        //打印1~10
+        int i = 1;
+        while(i<=10){
+            System.out.println(i);
+            i++;
+        }
+        System.out.println("------------------");
+        //打印10~1
+        int j = 10;
+        while (j>=1) {
+            System.out.println(j);
+            j--;
+        }
+        System.out.println("------------------");
+
+        //打印A~Z
+        int k = 'A';
+        while (k <= 'Z') {
+            System.out.println((char)k);
+            k++;
+        }
+    }
+}