数据类型扩展

public class demo02 {
    public static void main (String[] args) {
        //整数拓展 进制: 二进制0b 八进制0 十进制 十六进制 0x
        int i1 = 10;
        int i2 = 010;
        int i3 = 0x10;
        System.out.println (i1);
        System.out.println (i2);//八进制
        System.out.println (i3);//十六进制
        float f = 0.1f;
        double d = 1.0 / 10;
        System.out.println (f);
        System.out.println (d);
        System.out.println (f == d);
        float d1 = 12311231321321f;
        float d2 = d1 + 1;
        System.out.println (d1 == d2);//true
        //字符拓展
        char f1 = 'A';
        char f2 = '中';
        System.out.println ((int) f1);//强制转换成int类型
        System.out.println ((int) f2);
        char f3 = '\u0061';
        System.out.println (f3);
        System.out.println ("Hello\tWorld");
        String sa = new String ("hello word");
        String sb = new String ("hello word");
        System.out.println (sa == sb);//false

        String sc = "hello world";
        String sd = "hello world";
        System.out.println (sc==sd);//true
        //布尔值扩展
        boolean flag = true;
        if (flag==true){}
        if (flag){}

    }
}