! (Logical negation)
- Boolean operators
These operators can be used in if conditional statement.
- &&(Logical and)
Only both the two operands are true is it be true. For example:
if (digitalRead(2) == HIGH && digitalRead(3) == HIGH) { // read the levels of the two switch // ... }
When both input levels are high levels, it is true.
- ||(Logical or)
If only one operand is true, it is true. For example:
if (x > 0 || y > 0) { // ... }
If x or y is larger than 0, it is true
- !(Logical negation)
If operand is false, it is true For example
if (!x) { // ... }
If x is false, it is true(namely, x is equal to 0).
- For example
if (a >= 10 && a <= 20){} // if the value of a is between 10 and 20, it is true
- Note
You mustn't take the bitwise operator “and” whose sign is &(single) as same to boolean operator“and” whose sign is &&(double), which are completely different operators.
In the same way, don’t mix boolean operator || and bitwise operator “or”| up .
Bitwise operator 〜(tilde)looks like very different from boolean operator not!(just as the programmer say :“bang”). But you still should to confirm which operator you want.