A very complex Boolean expression may use several logical operators like the one shown here
PHP
($x > $y)  ($x == 5) && ($x <= $z)  !($z == 1)
So, a reasonable question is “which logical operation is performed first?”
The order of precedence is: logical complements (!) are performed first, logical conjunctions (&&) are performed next, and logical disjunctions () are performed at the end.
Higher Precedence Lower Precedence 
Logical Operator 
! 

&& 

 
Java, C++, C#
(x > y)  (x == 5) && (x <= z)  !(z == 1)
So, a reasonable question is “which logical operation is performed first?”
The order of precedence is: logical complements (!) are performed first, logical conjunctions (&&) are performed next, and logical disjunctions () are performed at the end.
Higher Precedence Lower Precedence 
Logical Operator 
! 

&& 

 
Visual Basic
(x > y) Or (x = 5) And (x <= z) Or Not(z = 1)
So, a reasonable question is “which logical operation is performed first?”
The order of precedence is: logical complements (Not
) are performed first, logical conjunctions (And
) are performed next, and logical disjunctions (Or
) are performed at the end.
Higher Precedence Lower Precedence 
Logical Operator 





Python
(x > y) or (x == 5) and (x <= z) or not(z == 1)
So, a reasonable question is “which logical operation is performed first?”
The order of precedence is: logical complements (not
) are performed first, logical conjunctions (and
) are performed next, and logical disjunctions (or
) are performed at the end.
Higher Precedence Lower Precedence 
Logical Operator 





Notice: You can always use parentheses to change the default precedence.