Is it possible to assign a test result to a boolean variable in Java?

Question

When I write boolean bool = aString.indexOf(subString) != -1Eclipse did not complain, does it mean the same thing boolean bool = aString.indexOf(subString) != -1 ? true : false?

Answer 1

Yes. Comparison gives a logical value and can be assigned to a variable in the same way as any other value.

The second form (with ternary operator ?:) is redundant and should not be used.

Stylistically, I usually enclose logical expressions in parentheses when assigning values ​​to them, since

boolean bool = (aString.indexOf(subString) != -1);

to make a strong visual distinction between two statements using a symbol =, but this is not required.

Answer 2

, .

, .

boolean bool = (aString.indexOf(subString) != -1);

Answer 3

Yes of course. A boolean expression returns a boolean value. Therefore, it can be used in operators if, etc., because they expect results trueor false.