Java.math.BigInteger.and（）如何工作？

Question

According to this tutorial the result from Java.math.BigInteger.and() when calling .and() with values 6 and 3 is 2. How does this work? It's neither concatenating nor adding.

Answer 1

Logical bitwise And operation

6 = 110b (b means binary)
3 = 011b

110b & 011b = 010b = 2

Answer 2

AND Truth table is following for 2 inputs

so for two integers 3 and 4

3 = 011b
4 = 100b

b means in base 2.

The and operation of 3&4 = 011&100.

so applying AND truth table for each bit position we get

1&0 = 0

1&0 = 0

0&1 = 1

Actually, I am applying and operation LSB to MSB for both numbers.

Now Biginteger class is introduced for calculating the large number which does not fit primitive data types long int .

BigInteger will do the same operation but for too big numbers.

Answer 3

Its bitwise And operation.In your question given link shows,

110 & 011 = 010
110 is the binary value of 6.
011 is the binary value of 3.

The result 010 is the binary of 2(decimal) .

Answer 4

It does the & (Bitwise And). Which means it returns the matching 1's in its binary representation. For example, 6 is 0110, 3 is 0011 so: 6 & 3 is 0110 & 0011 = 0010 = 2

Answer 5

BigInteger in java is same like primitive types int and long.All Bitwise operations that you are doing on numeric primitive types is same as and(),or(),xor() methods of BigInteger.BigInteger is like unlimited integer there is no fixed memory for it (for example int is 4 bytes Minimum value is - 2,147,483,648.(-2^31) Maximum value is 2,147,483,647(inclusive).(2^31 -1)).Your BigInteger is internally stored as

final int[] mag;

For and() method If your BigInteger value is more than int type it will add to array.Bitwise operations are done between array of interger on both inputs for example you have two bigintegers x and y

It will calculate like x.mag[0] & y.mag[0] x.mag[1] & y.mag[1] . . Add those all values returned by each and sum it up and give you final value.Finally its same like Bitwise operations &,|;