布尔运算符
These can be used inside the condition of an if statement.
这些可以使用于 if 语句中的条件判断。
&& (逻辑与)
True only if both operands are true, e.g.
if (digitalRead(2) == HIGH && digitalRead(3) == HIGH) { // read two switches // ... }
is true only if both inputs are high.
|| (逻辑或)
True if either operand is true, e.g.
if (x > 0 || y > 0) { // ... }
is true if either x or y is greater than 0.
! (取反)
True if the operand is false, e.g.
if (!x) { // ... }
is true if x is false (i.e. if x equals 0).
警告:
Make sure you don't mistake the boolean AND operator, && (double ampersand) for the bitwise AND operator & (single ampersand). They are entirely different beasts.
Similarly, do not confuse the boolean || (double pipe) operator with the bitwise OR operator | (single pipe).
The bitwise not ~ (tilde) looks much different than the boolean not ! (exclamation point or "bang" as the programmers say) but you still have to be sure which one you want where.
示例
if (a >= 10 && a <= 20){} // true if a is between 10 and 20
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