爪哇笔记04

java.util.Scanner s = new java.util.Scanner(System.in);

1.接收用户的输入，创建一个键盘扫描器对象

int i = s.nextInt();//int类型
String str = s.next();//字符串类型
float b = s.nextFloat();//浮点类型

public class Project02 {
    public static void main(String[] args) {
        java.util.Scanner s = new java.util.Scanner(System.in);
        System.out.println("Please input the month you want to search");
        int month = s.nextInt();
        if (month == 3 || month == 4 || month == 5){
            System.out.println("Spring");
        }
        if (month == 6 || month == 7 || month == 8) {
            System.out.println("Summer");
        }
        if (month == 9 || month == 10 || month == 11){
            System.out.println("Autumn");
        }
        if (month == 12 || month == 1 || month == 2){
            System.out.println("Winter");
        }
    }
}

public class Project03 {
    public static void main(String[] args) {
        java.util.Scanner s = new java.util.Scanner(System.in);
        System.out.println("Please input the month you want to search");
        int month = s.nextInt();
        switch (month)
        {
            case(3): case(4): case(5):
            System.out.println("Spring");
            break;
            case(6): case(7): case(8):
            System.out.println("Summer");
            break;
            case(9): case(10): case(11):
            System.out.println("Autumn");
            break;
            case(12): case(1): case(2):
            System.out.println("Winter");
            break;
        }
    }
}

以上为Switch与if的对比

public class Project04 {
    public static void main(String[] args) {
        java.util.Scanner s = new java.util.Scanner(System.in);
        System.out.println("Please input a number");
        int number_a = s.nextInt();
        if (number_a > 0){
            System.out.println("The number is a positive number");
        } else if (number_a < 0) {
            System.out.println("The number is a negative number");
        } else if (number_a == 0) {
            System.out.println("The number is zero");
        }
    }
}

public class Fibonacci01 {
    public static void main(String[] args) {
        int number_a = 1, number_b = 1, output = 0;
        java.util.Scanner s = new java.util.Scanner(System.in);
        int n = s.nextInt();
        if (n<=2){
            switch (n){
                case (0):
                    System.out.println("0");break;
                case (1): case (2):
                    System.out.println("1");break;
            }
        } else {
            for (int i=2;i<n;i++)
            {
                output = number_a + number_b;
                number_a = number_b;
                number_b = output;
            }
            System.out.println(output);
        }
    }
}

斐波那契数列的java实现方法1

public class Fibonacci02 {
    public static void main(String[] args) {
        int number[] = new int[400];
        int output = 0;
        java.util.Scanner s = new java.util.Scanner(System.in);
        int n = s.nextInt();
        number[0] = 0;
        number[1] = number[2] = 1;
        if (n <= 2) {
            switch (n) {
                case (0):
                    System.out.println("0");
                    break;
                case (1):
                case (2):
                    System.out.println("1");
                    break;
            }
        } else {
            for (int i = 2; i <= n; i++) {
                number[i] = number[i - 2] + number[i - 1];
                output = number[i];
            }
            System.out.println(output);
        }
    }
}

斐波那契数列的第二种实现方式