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## Logical Operators

Logical Operators
Example Name Result
\$a and \$b And TRUE if both \$a and \$b are TRUE.
\$a or \$b Or TRUE if either \$a or \$b is TRUE.
\$a xor \$b Xor TRUE if either \$a or \$b is TRUE, but not both.
! \$a Not TRUE if \$a is not TRUE.
\$a && \$b And TRUE if both \$a and \$b are TRUE.
\$a || \$b Or TRUE if either \$a or \$b is TRUE.

The reason for the two different variations of "and" and "or" operators is that they operate at different precedences. (See Operator Precedence.)

Example#1 Logical operators illustrated

<?php

// foo() will never get called as those operators are short-circuit
\$a = (false && foo());
\$b = (true  || foo());
\$c = (false and foo());
\$d = (true  or  foo());

// "||" has a greater precedence than "or"
\$e false || true// \$e will be assigned to (false || true) which is true
\$f false or true// \$f will be assigned to false
var_dump(\$e\$f);

// "&&" has a greater precedence than "and"
\$g true && false// \$g will be assigned to (true && false) which is false
\$h true and false// \$h will be assigned to true
var_dump(\$g\$h);

The above example will output something similar to:

bool(true)
bool(false)
bool(false)
bool(true)