Take a look at code showing each step that helps you understand a little better.
0x80 is the hexadecimal of decimal number 128. Which in binary is
10000000 . When it applies the operator
and , each bit of a number is compared to another and the result will be 1 if both are 1, or 0 if both are 0 or if only one of them is 1. This is how this operator works. Then in the example of the letter
t it starts with
You gave zero.
In the next step, the operator
<< is applied, which is the offset, that is, it throws all the bits to the left, so it looks like this:
You gave 128, that is, greater than zero, so he knows that he should use the string
And do this with all the other bits.
Note that using 128 (0x80) we are always comparing only the first bit. Or others will always give 0 in any situation, since at number 128, all bits will be 0, except the first. The
and operator, in this case, will only vary according to the first bit of the number. The rest will be 0.
This is how to walk step by step through the bits and analyze only the first. There are even other ways, but it will be less efficient.
See the inefficient way in dotNetFiddle . It may seem more readable to anyone who does not understand bit operators.
See the performance test at dotNetFiddle .
If you consider that other operations of the algorithm have a very high cost, the simple use of the bit operator instead of the arithmetic operator probably generates more than one order of magnitude in the isolated operation.
The test should be done on your computer. DotNetFiddle is not trusted by having multiple processes running at the same time. But it gives an initial basis.