#bitwise-operators

Solution: What do two left angle brackets mean? #fix #computers #it

What do two left angle brackets mean?

I saw a loop which I’ve never seen before:

for (int i = 0; i < (1 << list.Count); i++)

I can’t understand what (1 << list.Count) means, maybe someone could explain me this?

Original post

How to: Precedence and bitmask operations

Precedence and bitmask operations

I’ve come across a (seemingly) very strange case.

Take the number 2 (0b10) and bitmask it with 1 (0b01)

This should produce 0b00 which is equivalent to 0.

However, here’s where Mr Schrödinger comes in:

var_dump(0b10 & 0b01); // int(0) var_dump(0b10 & 0b01 == 0); // int(0) var_dump(0b10 & 0b01 != 0); // int(0)

Whiskey. Tango. Foxtrot.

I am, admittedly, not the…

How to: Why do we usually use `||` not `|`, what is the difference?

Why do we usually use `||` not `|`, what is the difference?

I’m just wondering why we usually use logical OR || between two booleans not bitwise OR |, though they are both working well.

I mean, look at the following:

if(true | true) // pass if(true | false) // pass if(false | true) // pass if(false | false) // no pass

if(true || true) // pass if(true || false) // pass if(false || true) // pass…