添加注释

CSapprenticeWT · CSapprenticeWT · commit 9e5b8601634e · 2022-12-13T12:15:18.000+08:00
diff --git a/operators/DoubleEquivalence.java b/operators/DoubleEquivalence.java
@@ -1,68 +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) {
-
-    //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
-*/
+// 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*/
