If I have the number '00001000' and the mask '00101000', how can i check, with a binary operation, if both the bits in the number are set? number & mask return true if at least one bit match, but I need to check for all of them to match.
How to?
If I have the number '00001000' and the mask '00101000', how can i check, with a binary operation, if both the bits in the number are set? number & mask return true if at least one bit match, but I need to check for all of them to match.
How to?
1 Answer
Reset to default 15Just pare to the mask:
if ((number & mask) === mask) {
// all bits are set!
}
The only way the result of the & operation will be exactly the same as the value of the mask is when the number has all the bits set. (The test number may have more bits set; if you want to check to see if it's got exactly the same bits set and unset, then that's a simple equality test.)