Java 用標志位表示狀態

 

public class JavaFlag {

    //    private static int BRAND_
    private static int BRAND_NO_SET = 0; // 0
    private static int BRAND_A = 1 << 0; // 1
    private static int BRAND_B = 1 << 1; // 2
    private static int BRAND_C = 1 << 2; // 4

    public static int mBrand = BRAND_NO_SET;

    public static void main(String[] args) {
        System.out.println(BRAND_NO_SET);
        System.out.println(BRAND_A);
        System.out.println(BRAND_B);
        System.out.println(BRAND_C);

        JavaFlag javaflag = new JavaFlag();
        javaflag.addSubBrand(BRAND_B);
        javaflag.addSubBrand(BRAND_A);
        javaflag.addSubBrand(BRAND_C);
        System.err.println(javaflag.mBrand);
        System.err.println(javaflag.mBrand);
        System.out.println(javaflag.mBrand & BRAND_A);
    }

    private void addSubBrand(int brand) {
        mBrand |= brand;
        System.out.println("添加品牌標志位:" + mBrand);
    }

    private void removeSubBrand(int brand) {
        mBrand &= ~brand;
        System.out.println("移除品牌標志位:" + mBrand);
    }

    private boolean hasSubBrand(int brand) {
        return (mBrand & brand) != 0;
    }

    private boolean isJustAllow(int brand) {
        return mBrand == brand;
    }
}

 

將十進制輸出為 二進制：

        System.out.println(Integer.toBinaryString(1 << 0));
        System.out.println(Integer.toBinaryString(1 << 1));
        System.out.println(Integer.toBinaryString(1 << 2));
        System.out.println(Integer.toBinaryString(1 << 3));
        System.out.println(Integer.toBinaryString(1 << 4));
        System.out.println(Integer.toBinaryString(1 << 5));
        System.out.println(Integer.toBinaryString(1 << 6));

輸出結果：

1
10
100
1000
10000
100000
1000000

 

https://blog.csdn.net/jdsjlzx/article/details/93977574