diff --git a/build.gradle b/build.gradle
index b4feb13d5..94d293993 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,7 +17,7 @@ subprojects {
     apply from: "$rootProject.projectDir/gradle/jmh.gradle"
     // apply from: "$rootProject.projectDir/gradle/checkstyle.gradle"
     apply from: "$rootProject.projectDir/gradle/findbugs.gradle"
-    apply plugin: 'com.mindviewinc.tagging'
+    //apply plugin: 'com.mindviewinc.tagging'
 }
 
 apply from: 'gradle/subprojects.gradle'
diff --git a/objects/HelloDate.java b/objects/HelloDate.java
index b408b1f48..a325d8f67 100644
--- a/objects/HelloDate.java
+++ b/objects/HelloDate.java
@@ -5,8 +5,14 @@
 import java.util.*;
 
 public class HelloDate {
-  public static void main(String[] args) {
-    System.out.println("Hello, it's: ");
-    System.out.println(new Date());
-  }
+//  public static void main(String[] args) {
+//    System.out.println("Hello, it's: ");
+//    System.out.println(new Date());
+//  }
+    public static void main(String[] args) {
+      System.out.println("------");
+      System.out.println(new Date());
+    }
 }
+
+
diff --git a/operators/Assignment.java b/operators/Assignment.java
index c4b9a793e..c8212653a 100644
--- a/operators/Assignment.java
+++ b/operators/Assignment.java
@@ -16,7 +16,8 @@ public static void main(String[] args) {
     t2.level = 47;
     System.out.println("1: t1.level: " + t1.level +
       ", t2.level: " + t2.level);
-    t1 = t2;
+    // t1 = t2; 引用
+    t1.level = t2.level; //实际对象
     System.out.println("2: t1.level: " + t1.level +
       ", t2.level: " + t2.level);
     t1.level = 27;
diff --git a/operators/Bool.java b/operators/Bool.java
index 42668315b..8e216d876 100644
--- a/operators/Bool.java
+++ b/operators/Bool.java
@@ -26,6 +26,7 @@ public static void main(String[] args) {
        + ((i < 10) && (j < 10)) );
     System.out.println("(i < 10) || (j < 10) is "
        + ((i < 10) || (j < 10)) );
+    //如果在应该使用字符串的地方使用了布尔值，布尔值会自动转换成合适的文本格式
   }
 }
 /* Output:
diff --git a/operators/DoubleEquivalence.java b/operators/DoubleEquivalence.java
index 5f06e25f5..0d3640990 100644
--- a/operators/DoubleEquivalence.java
+++ b/operators/DoubleEquivalence.java
@@ -1,49 +1 @@
-// operators/DoubleEquivalence.java
-// (c)2021 MindView LLC: see Copyright.txt
-// We make no guarantees that this code is fit for any purpose.
-// Visit http://OnJava8.com for more book information.
-
-public class DoubleEquivalence {
-  static void show(String desc, Double n1, Double n2) {
-    System.out.println(desc + ":");
-    System.out.printf(
-      "%e==%e %b %b%n", n1, n2, n1 == n2, n1.equals(n2));
-  }
-  @SuppressWarnings("deprecation")
-  public static void test(double x1, double x2) {
-    // x1.equals(x2) // Won't compile
-    System.out.printf("%e==%e %b%n", x1, x2, x1 == x2);
-    Double d1 = x1;
-    Double d2 = x2;
-    show("Automatic", d1, d2);
-    Double r1 = new Double(x1);
-    Double r2 = new Double(x2);
-    show("new Double()", r1, r2);
-    Double v1 = Double.valueOf(x1);
-    Double v2 = Double.valueOf(x2);
-    show("Double.valueOf()", v1, v2);
-  }
-  public static void main(String[] args) {
-    test(0, Double.MIN_VALUE);
-    System.out.println("------------------------");
-    test(Double.MAX_VALUE,
-      Double.MAX_VALUE - Double.MIN_VALUE * 1_000_000);
-  }
-}
-/* Output:
-0.000000e+00==4.900000e-324 false
-Automatic:
-0.000000e+00==4.900000e-324 false false
-new Double():
-0.000000e+00==4.900000e-324 false false
-Double.valueOf():
-0.000000e+00==4.900000e-324 false false
-------------------------
-1.797693e+308==1.797693e+308 true
-Automatic:
-1.797693e+308==1.797693e+308 false true
-new Double():
-1.797693e+308==1.797693e+308 false true
-Double.valueOf():
-1.797693e+308==1.797693e+308 false true
-*/
+// operators/DoubleEquivalence.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.

public class DoubleEquivalence {
  static void show(String desc, Double n1, Double n2) {
    System.out.println(desc + ":");
    System.out.printf(
      "%e==%e %b %b%n", n1, n2, n1 == n2, n1.equals(n2));
  }
  @SuppressWarnings("deprecation")
  public static void test(double x1, double x2) {
    // x1.equals(x2) // Won't compile
    System.out.printf("%e==%e %b%n", x1, x2, x1 == x2);

    Double d1 = x1;
    Double d2 = x2;
    show("Automatic", d1, d2);

    Double r1 = new Double(x1);
    Double r2 = new Double(x2);
    show("new Double()", r1, r2);

    Double v1 = Double.valueOf(x1);
    Double v2 = Double.valueOf(x2);
    show("Double.valueOf()", v1, v2);

  }
  public static void main(String[] args) {

    //比较0和最小的浮点数
    test(0, Double.MIN_VALUE);

    System.out.println("------------------------");

    //最大值 和 （最大值 和 （最小值只差的一百万倍））比较 一个非常大的数值减去一个相对较小的数值,
    //非常大的数值并不会发生显著变化。这个叫做 <b> 舍入误差 <\b>
    test(Double.MAX_VALUE,
      Double.MAX_VALUE - Double.MIN_VALUE * 1_000_000);

    System.out.println("------------------------");
    test(2.1, 3.5);

    System.out.println("------------------------");
    System.out.println(Double.MIN_VALUE); //2^-1074
    System.out.println(Double.MAX_VALUE);


  }
}
/* Output:
0.000000e+00==4.900000e-324 false
Automatic:
0.000000e+00==4.900000e-324 false false
new Double():
0.000000e+00==4.900000e-324 false false
Double.valueOf():
0.000000e+00==4.900000e-324 false false
------------------------
1.797693e+308==1.797693e+308 true
Automatic:
1.797693e+308==1.797693e+308 false true
new Double():
1.797693e+308==1.797693e+308 false true
Double.valueOf():
1.797693e+308==1.797693e+308 false true
*/
\ No newline at end of file
diff --git a/operators/Overflow.java b/operators/Overflow.java
index 68e494490..1a89a5561 100644
--- a/operators/Overflow.java
+++ b/operators/Overflow.java
@@ -8,7 +8,7 @@ public class Overflow {
   public static void main(String[] args) {
     int big = Integer.MAX_VALUE;
     System.out.println("big = " + big);
-    int bigger = big * 4;
+    int bigger = big * 4; // 数据不对 不是2147483647*4
     System.out.println("bigger = " + bigger);
   }
 }