int i = 10;
// 10 12 a 
printf("%d %o %x \n",i,i,i);
i = 21;
printf("%d %o %x \n",i,i,i);
i = -21;
-21 37777777753 ffffffeb 
printf("%d %o %x \n",i,i,i);
// 数字零开头 八进制
i = 012;
printf("%d %o %x \n",i,i,i);
i = 00012;
printf("%d\n",i);
	
i = 12;
printf("%d\n",i);

// 数字零x  六十进制
i = 0x12;
printf("%d\n",i); 
	



输出
10 12 a 
21 25 15 
-21 37777777753 ffffffeb 
10 12 a 
10
12
18



radix 基数


public class IntTest {	
	public static void main(String[] args) throws Exception {
		int value = 21;
		String str = Integer.toString(value, 2);
		System.out.println(str);
		System.out.println(Integer.parseInt(str, 2));

		toString(21);
		toString(-21);
	}
	
	private static void toString(int value) {
		StringBuilder sb = new StringBuilder();
		sb.append(value).append(" ");
		sb.append(Integer.toString(value, 2)).append(" ");
		sb.append(Integer.toString(value, 8)).append(" ");
		sb.append(Integer.toString(value, 16)).append(" ");
		sb.append(Integer.toBinaryString(value)).append(" ");
		sb.append(Integer.toOctalString(value)).append(" ");
		sb.append(Integer.toHexString(value)).append(" ");
		System.out.println(sb.toString());
	}

}

输出

10101
21
21 10101 25 15 10101 25 15 
-21 -10101 -25 -15 11111111111111111111111111101011 37777777753 ffffffeb