Modulo operation
Learn how to calculate the modulus of a division.
The modulo operation calculates the modulus of a division, which is the rest of the division that cannot be expressed as an exact multiple of the divisor.
While some languages use the %{:cql} symbol for performing the modulo operation, CQL uses the mod{:cql} keyword to avoid confusion with the percent operation.
To use the modulo operator, place the mod keyword between two numeric values:
/*<operand>*/ mod /*<operand>*/
You can also use the full name of the operation if you prefer:
/*<operand>*/ modulo /*<operand>*/
Here is a practical example:
7 mod 3 // 1
In the above example, the number 7 cannot be completely divided by 3, and there is a remainder of 1.
It is important to emphasize that modulo calculates the modulus and not the remainder. Although they may appear to be the same in many cases, there is a difference when dealing with negative numbers.
Imagine a scenario where you are dividing -7 by 3:
- The remainder would be -1, as this is the difference between -7 and -6, which is the nearest multiple of 3 that is less than -7.
- The modulus would be 2, as this is the difference between -7 and -9, which is the nearest multiple of 3 that is greater than -7.
Since CQL uses the modulus definition, the result of the above operation is 2.