2021.10.2

public class deamo {
    public static void main(String[] args) {
        System.out.println("Hello World");
        //这个是输出Hello的命令
        /*这个是多层注释的符号
         */
        /**这个是文件名的注释符号
         */
        String name ="梁森";
        System.out.println(name);
        String name1 ="yyds";
        System.out.println(name1);
        int nmu1 =10;
        System.out.println(nmu1);
        short num2 =40;
        System.out.println(num2);
        long num3 =40000L;
        System.out.println(num3);
        float num4 =3.14F;
        System.out.println(num4);
        double num5 =3.14159265358;
        System.out.println(num5);
        byte num6 =60;
        System.out.println(num6);
        int num7 =80;
        if (num7!=80){
            System.out.println("对不起，您拨打的电话不存在");
        }else{
            System.out.println("欢迎拨打电话");
        }
        int d1 =10;
        int d2 =010;     //二进制
        int d3 =0x10;    //十六进制
        System.out.println(d1);
        System.out.println(d2);
        System.out.println(d3);
        System.out.println("------------------------------------------------");
        float d4 =0.1f;
        double d5 =1.0/10f;
        System.out.println(d4 == d5);   //flase
        float d6 = 212121212121212f;
        float d7 = d6 + 1;
        System.out.println(d6==d7);     //true
        char c1 ='a';
        System.out.println(c1);
        System.out.println((int)c1);
        char c2 ='中';
        System.out.println(c2);
        System.out.println((int)c2);
        char c3 ='x';
        System.out.println(c3);
        System.out.println((int)c3);
        char c4 ='X';
        System.out.println(c4);
        //下面的代买是 I LOVE YOU
        System.out.println("---------------------------------------------------------");
        System.out.println((int)c4);
        char c5 ='I';
        System.out.println((int)c5);
        char c6 ='L';
        System.out.println((int)c6);
        char c7 ='O';
        System.out.println((int)c7);
        char c8 ='V';
        System.out.println((int)c8);
        char c9 ='E';
        System.out.println((int)c9);
        char c10 ='Y';
        System.out.println((int)c10);
        char c11 ='O';
        System.out.println((int)c11);
        char c12 ='U';
        System.out.println((int)c12);
        //下面的是你是个好人的代码
        char c13 ='你';
        char c14 ='是';
        char c15 ='个';
        char c16 ='好';
        char c17 ='人';
        System.out.println((int)c13);
        System.out.println((int)c14);
        System.out.println((int)c15);
        System.out.println((int)c16);
        System.out.println((int)c17);
        System.out.println("------------------------------------------------------");
        int d8 =97;
        System.out.println((char)d8);
        int d9 =65;
        System.out.println((char)d9);
        int d10 =120;
        System.out.println((char) d10);
        System.out.println("------------------------------------------------------");
        char c20='\u0061';
        System.out.println(c20);
        char c21 ='a';
        System.out.println((int)c21);
        System.out.println("Hello\tWorld");//   \为空格
        System.out.println("Hello\nWorld");//   \为转行
        System.out.println("------------------------------------------------------");
        //下面是面向对象不同而导致的结果不同
        String sa =new String("Hello\tWorld");
        String sb =new String("Hello\tWorld");
        System.out.println(sa==sb);        //flase     面向了另一个文件当中的Hello World     也是新建一个文档(new)
        String sc ="Hello\tWorld";
        String sd ="Hello\tWorld";
        System.out.println(sc==sd);        //true      同一个文件中的Hello World
        System.out.println("------------------------------------------------------");

    }
}