CODEWITHSUNDEEP
pythonbitwise-operators
NomardicRoku
NomardicRoku

Reputation: 81

Bitwise operations giving unexpected outcomes

I try to understand the difference between the logical operand and and the bitwise operand &. So I wrote two statements and get unexpected outcomes. I understand the first one and expect the second one would give me the same outcome as the first one.

  1. The first one I get the False which is what I want. But the second one I get True which makes me confused.

  2. Since 3%3 == 0 return True,and 3%5 == 0 return False. And True & False gives me False. Why, when I put them together, do I get the True? Can someone explain why the second one gives me the True instead of False?

    3 % 3 == 0 and 3 % 5 == 0
3 % 3 == 0 & 3 % 5 ==0 
3 % 3 == 0
3 % 5 == 0
True & False

Upvotes: 0

Views: 122

Answers (2)

Pac0
Pac0

Reputation: 23174

Operators priority is probably the source of confusion here.

& has higher precedence than ==, whereas and has a lower one.

This means the second case is the same as 3 % 3 == (0 & 3 % 5) == 0

If you add more parenthesis to show the order, these are equivalent:

(3 % 3) == (0 & (3 % 5)) == 0
0 == (0 & 3) == 0
0 == 0 == 0  // True

Note: the last chain of == is interpreted as the equality test between all three operands, and is obviously true here. Thanks @kaya for clarification comment.

Upvotes: 5

user14248283
user14248283

Reputation:

Remember than and means that both the expressions must be correct

3 % 3 == 0 and 3 % 5 == 0

print( 3 % 3 )

0

  • Hence, the first part is true
print( 3 % 5)

3

  • Hence, the second part is False, since the expression does not evaluate to 0

So if we simplify it, it becomes

3 % 3 == 0 and 3 % 5 == 0

True and False:

Both conditions are not true, hence the answer is false.

3 % 3 == 0 & 3 % 5 == 0

The answer comes when we look at operator precendence & has a higher precedence than == Hence, the statement is basically

3 % 3 == (0 & 3) % 5 == 0

Upvotes: 2

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