语法/运算符Java - 这行是什么意思？

Question

I've found one line in Java like this :

result |= (b & 0x1f) << shift;

I've searched about what operators do but I'm still not able to understand what it is supposed to do assuming result , b and shift are integer values.
Could anyone tell me what does this line is supposed to do ?

- Here is the sample part of the code found here

int b, shift = 0, result = 0;
do {
    b = encoded.charAt(index++) - 63;
    result |= (b & 0x1f) << shift;
    shift += 5;
} while (b >= 0x20);

Answer 1

Maybe this explanation might help you:

A. (b & 0x1f) : performs a logical AND operation between b and 0xf1 . This means: return the last 5 bits of b

B. A << shift : shifts to the left an amount of shift bits the result of A operation. This means: shift the last 5 bits of b an amount of shift bits to the left.

C. result |= B : assigns to result variable the result of perform a logical OR operation between result itself and the result of B operation. This means: perform a logical OR between result and the last 5 bits of b shifted to the left an amount of shift bits, and then assign the result to result variable.

Hope it be understandable.

Answer 2

It preserves the last 5 bits of b, left shifts them some amount and ors them into result.

In this case it is reversing the process described here: https://developers.google.com/maps/documentation/utilities/polylinealgorithm