import java.awt.*; import java.awt.event.*; import java.util.*; public class Main{ public static double max(double...values) { double largest=Double.MIN_VALUE; for (double v:values) if(v>largest) largest=v; return largest; } public static void main(String args[]) { System.out.println("Max:"+max(1,11,300,2,3)); } }
// MethodOverload.java // Using overloaded methods public class Main { public static void main(String[] args) { System.out.println("The square of integer 7 is " + square(7)); System.out.println("\nThe square of double 7.5 is " + square(7.5)); } public static int square(int x) { return x * x; } public static double square(double y) { return y * y; } }
import java.math.BigInteger; import java.util.Scanner; public class CalculateN { /** * @param args */ public static void main(String[] args) { System.out.print("请输入N:"); Scanner scanner=new Scanner(System.in); int number=scanner.nextInt(); System.out.println(number+"!="+calculateN2(number)); } public static long calculateN(int n) { if(n==1 || n==0){ return 1; } return n*calculateN(n-1); } public static BigInteger calculateN2(int n) { if(n==1 || n==0){ return BigInteger.valueOf(1); } return BigInteger.valueOf(n).multiply(calculateN2((n-1))); } }
import java.util.Random; public class Main { public static void main(String[] args) { Random r1 = new Random(50); System.out.println("第一个种子为50的Random对象"); System.out.println("r1.nextBoolean():\t" + r1.nextBoolean()); System.out.println("r1.nextInt():\t\t" + r1.nextInt()); System.out.println("r1.nextDouble():\t" + r1.nextDouble()); System.out.println("r1.nextGaussian():\t" + r1.nextGaussian()); System.out.println("---------------------------"); Random r2 = new Random(50); System.out.println("第二个种子为50的Random对象"); System.out.println("r2.nextBoolean():\t" + r2.nextBoolean()); System.out.println("r2.nextInt():\t\t" + r2.nextInt()); System.out.println("r2.nextDouble():\t" + r2.nextDouble()); System.out.println("r2.nextGaussian():\t" + r2.nextGaussian()); System.out.println("---------------------------"); Random r3 = new Random(100); System.out.println("种子为100的Random对象"); System.out.println("r3.nextBoolean():\t" + r3.nextBoolean()); System.out.println("r3.nextInt():\t\t" + r3.nextInt()); System.out.println("r3.nextDouble():\t" + r3.nextDouble()); System.out.println("r3.nextGaussian():\t" + r3.nextGaussian()); Random r4 = new Random(System.currentTimeMillis()); System.out.println("以当前时间为种子的Random对象"); System.out.println("r3.nextBoolean():\t" + r4.nextBoolean()); System.out.println("r3.nextInt():\t\t" + r4.nextInt()); System.out.println("r3.nextDouble():\t" + r4.nextDouble()); System.out.println("r3.nextGaussian():\t" + r4.nextGaussian()); } }
import java.util.*; public class Main { public static void main(String[] args) { Random rand = new Random(); System.out.println("rand.nextBoolean():" + rand.nextBoolean()); byte[] buffer = new byte[16]; rand.nextBytes(buffer); System.out.println(Arrays.toString(buffer)); //生成0.0~1.0之间的伪随机double数 System.out.println("rand.nextDouble():" + rand.nextDouble()); //生成0.0~1.0之间的伪随机float数 System.out.println("rand.nextFloat():" + rand.nextFloat()); //生成平均值是 0.0,标准差是 1.0的伪高斯数 System.out.println("rand.nextGaussian():" + rand.nextGaussian()); //生成一个处于long整数取值范围的伪随机整数 System.out.println("rand.nextInt():" + rand.nextInt()); //生成0~26之间的伪随机整数 System.out.println("rand.nextInt(26):" + rand.nextInt(26)); //生成一个处于long整数取值范围的伪随机整数 System.out.println("rand.nextLong():" + rand.nextLong()); } }
public class Main { public static void main(String[] args) { /*---------下面是三角运算---------*/ //将弧度转换角度 System.out.println("Math.toDegrees(1.57):" + Math.toDegrees(1.57)); //将角度转换为弧度 System.out.println("Math.toRadians(90):" + Math.toRadians(90)); //计算反余弦,返回的角度范围在 0.0 到 pi 之间。 System.out.println("Math.acos(0.3):" + Math.acos(1.2)); //计算反正弦;返回的角度范围在 -pi/2 到 pi/2 之间。 System.out.println("Math.asin(0.8):" + Math.asin(0.8)); //计算反正切;返回的角度范围在 -pi/2 到 pi/2 之间。 System.out.println("Math.atan(2.3):" + Math.atan(2.3)); //计算三角余弦。 System.out.println("Math.cos(1.57):" + Math.cos(1.57)); //计算值的双曲余弦。 System.out.println("Math.cosh(1.2 ):" + Math.cosh(1.2 )); //计算正弦 System.out.println("Math.sin(1.57 ):" + Math.sin(1.57 )); //计算双曲正弦 System.out.println("Math.sinh(1.2 ):" + Math.sinh(1.2 )); //计算三角正切 System.out.println("Math.tan(0.8 ):" + Math.tan(0.8 )); //计算双曲余弦 System.out.println("Math.tanh(2.1 ):" + Math.tanh(2.1 )); //将矩形坐标 (x, y) 转换成极坐标 (r, thet));,返回所得角 theta。 System.out.println("Math.atan2(0.1, 0.2):" + Math.atan2(0.1, 0.2)); /*---------下面是取整运算---------*/ //取整,返回小于目标数的最大整数。 System.out.println("Math.floor(-1.2 ):" + Math.floor(-1.2 )); //取整,返回大于目标数的最小整数。 System.out.println("Math.ceil(1.2):" + Math.ceil(1.2)); //四舍五入取整 System.out.println("Math.round(2.3 ):" + Math.round(2.3 )); /*---------下面是乘方、开方、指数运算---------*/ //计算平方根。 System.out.println("Math.sqrt(2.3 ):" + Math.sqrt(2.3 )); //计算立方根。 System.out.println("Math.cbrt(9):" + Math.cbrt(9)); //返回欧拉数 e 的n次幂。 System.out.println("Math.exp(2):" + Math.exp(2)); //返回 sqrt(x2:" +y2),没有中间溢出或下溢。 System.out.println("Math.hypot(4 , 4):" + Math.hypot(4 , 4)); // 按照 IEEE 754 标准的规定,对两个参数进行余数运算。 System.out.println("Math.IEEEremainder(5 , 2):" + Math.IEEEremainder(5 , 2)); //计算乘方 System.out.println("Math.pow(3, 2):" + Math.pow(3, 2)); //计算自然对数 System.out.println("Math.log(12):" + Math.log(12)); //计算底数为 10 的对数。 System.out.println("Math.log10(9):" + Math.log10(9)); // 回参数与 1 之和的自然对数。 System.out.println("Math.log1p(9):" + Math.log1p(9)); /*---------下面是符号相关的运算---------*/ //计算绝对值。 System.out.println("Math.abs(-4.5):" + Math.abs(-4.5)); //符号赋值,返回带有第二个浮点数符号的第一个浮点参数。 System.out.println("Math.copySign(1.2, -1.0):" + Math.copySign(1.2, -1.0)); //符号函数;如果参数为 0,则返回 0;如果参数大于 0,则返回 1.0;如果参数小于 0,则返回 -1.0。 System.out.println("Math.signum(2.3):" + Math.signum(2.3)); /*---------下面是大小相关的运算运算---------*/ //找出最大值 System.out.println("Math.max(2.3 , 4.5):" + Math.max(2.3 , 4.5)); //计算最小值 System.out.println("Math.min(1.2 , 3.4):" + Math.min(1.2 , 3.4)); //返回第一个参数和第二个参数之间与第一个参数相邻的浮点数。 System.out.println("Math.nextAfter(1.2, 1.0):" + Math.nextAfter(1.2, 1.0)); //返回比目标数略大的浮点数 System.out.println("Math.nextUp(1.2 ):" + Math.nextUp(1.2 )); //返回一个伪随机数,该值大于等于 0.0 且小于 1.0。 System.out.println("Math.random():" + Math.random()); } }
public class Main{ public static void main(String[] args) { int result; for (int x = 1; x <= 10; x++) { result = square(x); // Math库中也提供了求平方数的方法 // result=(int)Math.pow(x,2); System.out.println("The square of " + x + " is " + result + "\n"); } } // 自定义求平方数的静态方法 public static int square(int y) { return y * y; } }
// RollDie.java // Roll a six-sided die 6000 times import javax.swing.*; public class Main { public static void main( String args[] ) { int frequency1 = 0, frequency2 = 0, frequency3 = 0, frequency4 = 0, frequency5 = 0, frequency6 = 0, face; // summarize results for ( int roll = 1; roll <= 6000; roll++ ) { face = 1 + (int) ( Math.random() * 6 ); switch ( face ) { case 1: ++frequency1; break; case 2: ++frequency2; break; case 3: ++frequency3; break; case 4: ++frequency4; break; case 5: ++frequency5; break; case 6: ++frequency6; break; } } JTextArea outputArea = new JTextArea( 7, 10 ); outputArea.setText( "Face\tFrequency" + "\n1\t" + frequency1 + "\n2\t" + frequency2 + "\n3\t" + frequency3 + "\n4\t" + frequency4 + "\n5\t" + frequency5 + "\n6\t" + frequency6 ); JOptionPane.showMessageDialog( null, outputArea, "Rolling a Die 6000 Times", JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }
// RandomInt.java // Shifted, scaled random integers import javax.swing.JOptionPane; public class Main { public static void main( String args[] ) { int value; String output = ""; for ( int i = 1; i <= 20; i++ ) { value = 1 + (int) ( Math.random() * 6 ); output += value + " "; if ( i % 5 == 0 ) output += "\n"; } JOptionPane.showMessageDialog( null, output, "20 Random Numbers from 1 to 6", JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }
import java.util.Random; import java.util.Scanner; public class Main { public static void main(String[] args) { int n=10000; Scanner scanner = new Scanner(System.in); int totalQuestions = 30; int correctAnswers = 0; int wrongAnswers = 0; int countdownSeconds = 100; // 设置倒计时秒数 // CountdownTimer countdownTimer = new CountdownTimer(countdownSeconds); // countdownTimer.start(); for (int i = 1; i <= totalQuestions; i++) { System.out.println("问题 " + i + ":"); String question = generateQuestion(); System.out.println(question); int userAnswer = scanner.nextInt(); int correctAnswer = evaluateQuestion(question); while (userAnswer == correctAnswer) { System.out.println("回答正确!\n"); System.out.println("倒计时\n"+n); n-=5; correctAnswers++; break; } while(userAnswer != correctAnswer) { System.out.println("回答错误。正确答案是: " + correctAnswer + "\n"); System.out.println("倒计时\n"+n); n-=3; wrongAnswers++; break; } } double accuracy = (double) correctAnswers / totalQuestions * 100; System.out.println("答题结束。正确答案数量: " + correctAnswers); System.out.println("错误答案数量: " + wrongAnswers); System.out.println("正确率: " + accuracy + "%"); scanner.close(); } private static int Judge(int a,int b,int c) { if(a==b){ System.out.println("回答正确!\n"); b++; return 0; }else{ System.out.println("回答错误,正确答案是:"+b+"\n"); c++; } return 0; } // 生成随机四则运算题目 private static String generateQuestion() { Random random = new Random(); int num1 = random.nextInt(100); int num2 = random.nextInt(100); int operator = random.nextInt(4); String op = ""; int answer = 0; switch (operator) { case 0: // Addition op = "+"; answer = num1 + num2; break; case 1: // Subtraction op = "-"; answer = num1 - num2; if (answer < 0) { // 确保减法不出现负数 num1 = num2 + random.nextInt(1000 - num2); // 重新生成num1 answer = num1 - num2; } break; case 2: // Multiplication op = "x"; num1 = random.nextInt(100); num2 = random.nextInt(100); answer = num1 * num2; if (answer >= 10000) { // 确保乘法不出现4位数 num1 = random.nextInt(100); num2 = random.nextInt(100); answer = num1 * num2; } break; case 3: // Division op = "/"; num2 = random.nextInt(10) + 1; // 避免除以0 num1 = num2 * random.nextInt(100); answer = num1 / num2; break; } return num1 + " " + op + " " + num2 + " = "; } // 计算四则运算题目的答案 private static int evaluateQuestion(String question) { String[] parts = question.split(" "); int num1 = Integer.parseInt(parts[0]); String operator = parts[1]; int num2 = Integer.parseInt(parts[2]); switch (operator) { case "+": return num1 + num2; case "-": return num1 - num2; case "x": return num1 * num2; case "/": return num1 / num2; default: throw new IllegalArgumentException("无效的运算符: " + operator); } } }
标签:Java,int,System,println,课堂,public,Math,out From: https://www.cnblogs.com/bzsc/p/17726686.html