Tell reason of output 2. When this code runs:

Question

#include <iostream>
using namespace std;

int main() {
cout<<(1<<1);
return 0;
}

Answer 1

Tip:
Left Shift by 1 = Multiplication by 2
Right Shift by 1 = Division by 2

Answer 2

In binary.
00000001
<< ( left shift ) one step
the result will be
00000010 ( 2 )

Answer 3

that implies <<<< =multiply 4

Answer 4

not at all.
let's the variable is declared as 8bit signed integer. ( byte )
the first bit is signed bit.
(0)100 0000 = 64
64 << 1 = (1)000 0000 = -128

according to the C Language standard.
The "byte" must be 8 bit.
you may declare it as unsigned (0-255).

for the type "int".
it is depends on the OS and the CPU.
Nowadays, it's usually 64bit length.

For Java, the int must be 32bit signed.
( Java can not unsigned )