JVAV

面向对象//if else while,for循环语句等语法和C是一样的

基础

import java.util.Scanner;

public class Hello {
    public static void main(String[] args) {

        //System.out.println("你好");
        Scanner in = new Scanner(System.in);
//        System.out.println("echo:"+in.nextLine());//加号连接字符串
        System.out.println("输入身高");
        double itch = 0;
        int foot = 0;
        foot = in.nextInt();
        itch = in.nextDouble();
        //类型转换(Element)(运算)
        System.out.println((int) ((foot + itch / 12) * (0.3048) * 100) + "cm");
//        System.out.println((10/3*3));//输出9
//        System.out.println((10/3.0*3));//输出10.0
//          System.out.println((10.0/3.0*3));//输出10.0
//        shift+方向键+ctrl+/


        //多路分支
        int type = 0;
        type = in.nextInt();
        switch (type) {
            case 1:
            case 2:
                System.out.println("hello");
                break;
            case 3:
                System.out.println("bye");
                break;
            default:
                System.out.println("what");
                break;
        }

        //随机数 Math.random();
        

        // /数组
        int[] a=new int[100];

        int[] b=new int [a.length];
        int[] data=new int[100];
        int x;
        boolean found=false;
        for(int k:a)//每次循环将数组a里面的值赋值给k，只是值的对应关系，与位置无关
        {
            if(k==x){found=true;}
        }
    }
    
}

面向对象