Math和Random

src/chapter5/Example16.java

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+package chapter5;
+
+public class Example16 {
+    public static void main(String[] args) {
+        System.out.println("计算绝对值的结果: " + Math.abs(-10));
+        System.out.println("求大于参数的最小整数: " + Math.ceil(5.6));
+        System.out.println("求小于参数的最大整数: " + Math.floor(-4.2));
+        System.out.println("对小数进行四舍五入后的结果: " + Math.round(-4.6));
+        System.out.println("求两个数的较大值: " + Math.max(2.1, -2.1));
+        System.out.println("求两个数的较小值: " + Math.min(2.1, -2.1));
+        System.out.println("生成一个大于等于0.0小于1.0随机值: " + Math.round(10 * Math.random()));
+        System.out.println("开平方的结果: "+Math.sqrt(4));
+        System.out.println("指数函数的值: "+Math.pow(2, 3));
+    }
+}

src/chapter5/Example17.java

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+package chapter5;
+
+import java.util.Random;
+
+public class Example17 {
+    public static void main(String[] args) {
+        Random r = new Random();    // 不传入种子
+        for (int i = 0; i < 10; i++) {
+            // 随机产生10个[0,100)之间的整数
+            System.out.println(r.nextInt(100));
+        }
+    }
+}

src/chapter5/Example18.java

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+package chapter5;
+
+import java.util.Random;
+
+public class Example18 {
+    public static void main(String[] args) {
+        Random r = new Random(13);
+        // 随机产生10个[0,100)之间的整数
+        for (int i = 0; i < 10; i++) {
+            System.out.println(r.nextInt(100));
+        }
+    }
+}

src/chapter5/Example20.java

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+package chapter5;
+
+public class Example20 {
+}

src/chapter5/Example21.java

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+package chapter5;
+
+public class Example21 {
+}