How the bitwise operator 'and' checks the number even or odd ???

Question

can anyone explain this with programming language please ??

Answer 1

Use 1 as a mask this will flip all bits except the ones place to 0. The result will only be 1 if the ones place is one which only occurs for odd numbers. Therefore, if the result is 0 the number is even, of the result is 1 the number is odd. This is also much faster than using the modulo operator as in (num % 2 == 0)

if(num & 1 == 0)
// number is even

10 = 00001010
1 = 00000001
& 00000000

if(num & 1 == 1)
// number is odd

15 = 00001101
1 = 00000001
& 00000001