java有趣的程序源代码(经典的java程序)

有趣的 Java 程序源代码
1. 九十九乘法表
java
public class MultiplicationTable {
public static void main(String[] args) {
for (int i = 1; i <= 9; i++) {
for (int j = 1; j <= 9; j++) {
System.out.print(i j + "\t");
}
System.out.println();
}
}
}
要素：
嵌套循环
格式化控制台输出
2. 斐波那契数列
java
public class Fibonacci {
public static void main(String[] args) {
int a = 0, b = 1, c;
System.out.print(a + " " + b + " ");
for (int i = 2; i < 20; i++) {
c = a + b;
System.out.print(c + " ");
a = b;
b = c;
}
System.out.println();
}
}
要素：
循环
变量赋值
格式化控制台输出
3. 质数检查器
java
import java.util.Scanner;
public class PrimeChecker {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter a number to check: ");
int num = input.nextInt();
boolean isPrime = true;
for (int i = 2; i <= num / 2; i++) {
if (num % i == 0) {
isPrime = false;
break;
}
}
if (isPrime) {
System.out.println(num + " is a prime number.");
} else {
System.out.println(num + " is not a prime number.");
}
input.close();
}
}
要素：
用户输入
循环
条件语句
格式化控制台输出