The code in question

Suddenly, the code below came out, and it was a story that I was wondering.

String str =Conditional expression 1?Conditional expression 2? "A" : "B" : "C";

To make a simple table, what kind of movement this will be

Conditional expression 1	Conditional expression 2	Output result
true	true	A
true	false	B
false	false	C
false	true	C

I found out when I put it together, but I was confused.

I put parentheses to make it easier to see

The ternary operator, which has multiple conditional expressions, is completely unfamiliar. I'll put parentheses so that it's easy for me to read.

String str =Conditional expression 1? (Conditional expression 2? "A" : "B") : "C";

This makes it a little easier to see. The next time you see a similar code, put parentheses (in your mind)! I will point out.

I tried to rewrite it as an if ~ else statement

After all, it was the easiest to understand if I rewrote it with an if ~ else statement.

String str = "";
if (Conditional expression 1) {
    if (Conditional expression 2) {
        str = "A";
    } else {
        str = "B";
    }
} else {
    str = "C";
}

If you express it with if ~ else, the number of lines will inevitably increase. So, I feel that the ternary operator can be written smarter.

I tried to make it easier to see by inserting line breaks

This is the method taught in the comments. Try inserting line breaks instead of parentheses.

String str =Conditional expression 1
    ?Conditional expression 2? "A" : "B"
    : "C";

It is common to write the ternary operator on one line, but it may be better to express it on multiple lines only when there are multiple conditions. I think it's easier to see than the parentheses. * It's just a personal feeling ...

I tried to rewrite the conditional branch

This is also the method taught in the comments. The conditions have been reviewed to make it easier to see.

String str = !Conditional expression 1? "C" :Conditional expression 2? "A" : "B";

If you break this further,

String str = 
        !Conditional expression 1? "C"
        :Conditional expression 2? "A"
        : "B";

It's much easier to read than the first ternary operator and the if ~ else statement.

Miscellaneous feelings

Recently, I am actively using the ternary operator. If you add a lambda expression or Stream API to it, you can express it with a fairly small number of lines, so I like it a lot.

However, if you use only ternary operators during code review, you will be asked "Isn't it low readability?" What should I do ...