javascript

Chapter 3: Language Basics
As an example, to AND the numbers 25 and 3 together, the code looks like this:
var result = 25 & 3;
alert(result); //1
The result of a bitwise AND between 25 and 3 is 1. Why is that? Take a look:
25 = 0000 0000 0000 0000 0000 0000 0001 1001
3 = 0000 0000 0000 0000 0000 0000 0000 0011
---------------------------------------------
AND = 0000 0000 0000 0000 0000 0000 0000 0001
As you can see, only one bit (bit 0) contains a 1 in both 25 and 3. Because of this, every other bit of the
resulting number is set to 0, making the result equal to 1.
Bitwise OR
The bitwise OR operator is represented by a single pipe character ( | ) and also works on two numbers.
Bitwise OR follows the rules in this truth table:
Bit from First Number Bit from Second Number Result
1 1 1
1 0 1
0 1 1
0 0 0
A bitwise OR operation returns 1 if at least one bit is 1. It returns 0 only if both bits are 0.
Using the same example as for bitwise AND, if you want to OR the numbers 25 and 3 together, the code
looks like this:
var result = 25 | 3;
alert(result); //27
The result of a bitwise OR between 25 and 3 is 27:
25 = 0000 0000 0000 0000 0000 0000 0001 1001
3 = 0000 0000 0000 0000 0000 0000 0000 0011
---------------------------------------------
OR = 0000 0000 0000 0000 0000 0000 0001 1011
In each number, four bits are set to 1, so these are passed through to the result. The binary code 11011 is
equal to 27.
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