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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" // The result of the expression (false || true) is assigned to \$e // Acts like: (\$e = (false || true))\$e = false || true; // The constant false is assigned to \$f and then true is ignored // Acts like: ((\$f = false) or true)\$f = false or true; var_dump(\$e, \$f); // -------------------- // "&&" has a greater precedence than "and" // The result of the expression (true && false) is assigned to \$g // Acts like: (\$g = (true && false))\$g = true && false; // The constant true is assigned to \$h and then false is ignored // Acts like: ((\$h = true) and false)\$h = true and false; var_dump(\$g, \$h);?>```

The above example will output something similar to:

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

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