Which operator cannot be used with if-else statement?

1. <=
2. ||
3. &&
4. ? :

? :

Reason — Relational operators ( <= ) and logical operators (|| and &&) can be used to test a condition as they return boolean values. Ternary operator (? :) is used to assign a value to a variable based on a condition. Thus, it cannot be used with if-else statement.