return (n > 2) ? n = 5 : n = 4; doesn't work?

Question

Why does this return an error

return (n > 2) ? n = 5 : n = 4;

but this does not

return (n > 2) ? n = 5 : n + 4;

Should it not be able to return n depending on either case?

What language are you asking for? In what context is this line? And what's the error you're getting? — Alejandro, Mar 14 '21 at 05:17
So ternary operators are used to return the value of the conditional statement variable only? — BabyProgrammer, Mar 14 '21 at 05:19
static int Func(int n) { return (n > 2) ? 5 : 4; } This is java syntax — BabyProgrammer, Mar 14 '21 at 05:22
update it in the question and also the error message, you got downvote for these — Towsif Ahamed Labib, Mar 14 '21 at 05:29

Progman · Accepted Answer · 2021-03-14T17:40:26.740

The code you have can't be compiled because the ternary operator has a higher operator precedence than the assignment operator:

Operator Precedence

postfix (expr++ expr--)

unary (++expr --expr +expr -expr ~ !)

...

ternary (? :)

assignment (= += -= *= /= %= &= ^= |= <<= >>= >>>=)

When parsing the code

(n > 2) ? n = 5 : n = 4;

it will parse it like this:

(n > 2) ? n = 5 : n     // ternary operator
                    = 4 // assignment operator

This would result in pseudo code like this:

someResultValue 
                = value;

That will not work and you get compile errors like:

'Syntax error on token "=", <= expected'

or

'Type mismatch: cannot convert from Object & Comparable<?> & Serializable to int'.

You can use parentheses to let java see the third argument of the ternary operator as n = 4. The code would look like this:

return (n > 2) ? n = 5 : (n = 4);

Thank you for the detailed answer, this is exactly what I was looking for. — BabyProgrammer, Mar 14 '21 at 12:35

Marmik Patel · Answer 2 · 2021-03-14T11:12:58.187

0

I think you may have any syntax error. I tried that in chrome JS console and worked fine!!

Update: Some people argued in comments that I didn't write function so I wrote in functional format and got the same result! enter image description here

edited Mar 14 '21 at 11:12

answered Mar 14 '21 at 05:20

Marmik Patel

21
1
4

Damn that's weird, it doesn't work in Java for some reason – BabyProgrammer Mar 14 '21 at 05:22
It isn't a return of a function, this answer lacks the main concept – Towsif Ahamed Labib Mar 14 '21 at 05:26

score 0 · Answer 3 · answered Mar 14 '21 at 05:22

syntax : condition ? expression1 : expression2;

Try this

public class Solution {
    public static void main(String[] args) throws IOException {
       int a = 10;
       int b = (a>5)?a=5:0;
       System.out.println("a = "+ a);
       System.out.println("b = "+b);
       
    }
}

output: a = 5 b = 5

return (n > 2) ? n = 5 : n = 4; doesn't work?

3 Answers3