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+.. highlight:: cpp
+
+.. _lang-boolean:
+
+Boolean Operators
+=================
+
+These can be used inside the condition of an :ref:`if <lang-if>`
+statement. Evaluate to :ref:`true <lang-constants-true>` or
+:ref:`false <lang-constants-false>`.
+
+.. contents:: Contents
+ :local:
+
+.. _lang-boolean-and:
+
+&& (logical and)
+----------------
+
+True only if both operands are true. For example::
+
+ if (digitalRead(2) == HIGH && digitalRead(3) == HIGH) { // read two switches
+ // ...
+ }
+
+is true only if both inputs are high. Another example::
+
+ if (a >= 10 && a <= 20){} // true if a is between 10 and 20
+
+**Be careful** not to say ``10 <= a <= 20``! This won't work the way
+you want. You have to separately test whether ``a`` is at least 10
+using ``a >= 10``, then test whether ``a`` is at most 20 using ``a <=
+20``, then combine the results using ``&&``.
+
+
+.. _lang-boolean-or:
+
+\|\| (logical or)
+-----------------
+
+True if either operand is true. For example::
+
+ if (x > 0 || y > 0) {
+ // ...
+ }
+
+is true if either ``x`` or ``y`` is greater than 0.
+
+.. _lang-boolean-not:
+
+! (logical not)
+---------------
+
+True if the operand is false. For example::
+
+ if (!x) {
+ // ...
+ }
+
+is true if ``x`` is false (i.e. if ``x`` is zero).
+
+Some Advice
+-----------
+
+.. warning::
+
+ Make sure you don't mistake the boolean AND operator ``&&``
+ (double ampersand) for the :ref:`bitwise AND operator
+ <lang-bitwisemath-and>` ``&`` (single ampersand). They are
+ entirely different beasts.
+
+ Similarly, do not confuse the boolean OR operator ``||`` (double
+ pipe) with the :ref:`bitwise OR operator <lang-bitwisemath-or>`
+ ``|`` (single pipe).
+
+ The :ref:`bitwise NOT operator <lang-bitwisemath-not>` ``~``
+ (tilde) looks much different than the boolean not operator ``!``
+ (exclamation point, or "bang", as some programmers say), but you
+ still have to be sure which one you want.
+
+
+See Also
+--------
+
+- :ref:`Bitwise operators <lang-bitwisemath>` (``&``, ``|``, ``^``, ``~``)
+- :ref:`Compound bitwise operators <lang-bitwisecompound>` (``&=``,
+ ``|=``, ``^=``).
+- :ref:`if statement <lang-if>`
+
+
+.. include:: cc-attribution.txt