Which operator would you use to ensure two values or variables are not equal in PHP?

The operator used to ensure that two values or variables are not equal in PHP is the inequality operator, represented as !=. This operator checks if the values being compared are not the same. If they are not equal, it returns true; otherwise, it returns false.

In contrast to other operators, != performs type juggling, meaning it will evaluate the equality of two values after converting them to a common type if they are of different types. For example, the expression 0 != "0" would evaluate to false because they are considered equal after type conversion.

It's worth noting that the strict inequality operator, !==, checks for both value and type. This means that if the values are not equal or if they are of different types, it returns true. The triple equals operator, ===, checks for strict equality, meaning both the value and type must be the same for it to return true.

Therefore, when you want to assert that two values are not equal, != is the appropriate choice as it allows for flexibility in type comparison.