In this section, we will discuss how to perform logical operations.
To check if either or both of two boolean values (like the results from comparison operations) are true, we use logical operators.
VCSSL supports the following logical operators:
| Symbol | Meaning | Supported Types | Details |
|---|---|---|---|
| && | Logical AND | bool | The result becomes true only when both the right and left values are true. If either one is false, the result becomes false. |
| || | Logical OR | bool | The result becomes true if either the right or left value is true. The result becomes false only when both the right and left values are false. |
| ! | Logical NOT | bool | The result becomes false if the value is true, and true if the value is false. |
Let's look at an example combining two comparison results:
- Execution Result -
When you execute this, it will display true. Both b1 and b2 are true, so b1 && b2 also becomes true.
Now, let's see what happens with the following:
- Execution Result -
This time, it will display false. While b1 is true, b2 is false, causing b1 && b2 to evaluate to false. The "&&" operator returns true only if all compared values are true.
In the previous examples, we firstly stored the results of comparison operations into bool type variables, and then performed logical operations on them. However, in practical code, it's cumbersome to create bool variables for every comparison.
Therefore, you can mix and write them as follows:
- Execution Result -
When you execute this, it will display true.
To process multiple logical operations together, you need to use parentheses like this:
- Execution Result -
This evaluates to "( true && true ) || ( false && false ) || false," which is equivalent to "true || false || false," so when executed, it displays true.
You may need the opposite of a comparison result (true becomes false, and vice versa). In such cases, you can use the negation symbol "!"
- Execution Result -
When you execute this, it displays false.