Can anyone tell me why 8>7<6 = true?

Question

Can anyone tell me why

8>7<6 = true
12>10>2 = false

Please give answer

Please Go through the image also

Thanks in Advance

In an MCQ interview they are asking these kind of stupid Question , they had given true false and error options Only — Rocky, Jul 20 '18 at 09:05
`8>7` is `true` and `true < 6` is `true` so `(8>7)<6 = true`. `12>10` is `true` and `true>2` is `false` so `(12>10)>2 = false` — t.niese, Jul 20 '18 at 09:06
It's a common misconception that there is a direct link between classical maths, & computer maths when it comes to writing them down,. The above in computer maths would be `8>6 && 7<6` and `12>10 && 10>2` — Keith, Jul 20 '18 at 09:28

score 8 · Answer 1 · answered Jul 20 '18 at 09:11

8

Here true = 1 and false =0 and expression evaluate from left to right

1) 8>7<6 = true

8>7 = true
true<6 = 1<6=true

2) 12>10>2 = false

12>10=true
  true>2 = 1>2= false

answered Jul 20 '18 at 09:11

Bhushan Kawadkar

8 is greater than 7 right? – Bhushan Kawadkar Jul 20 '18 at 09:12
@LouysPatriceBessette what is your problem with `8>7`? – t.niese Jul 20 '18 at 09:12
@LouysPatriceBessette what do you think it should be `8>7`? – Ankit Agarwal Jul 20 '18 at 09:12
@LouysPatriceBessette it's obviously being explicit as to show how the logic flows. – Rory McCrossan Jul 20 '18 at 09:13

Ankit Agarwal · Answer 2 · 2018-07-20T09:51:33.323

6

In javascript the comaprison expression is evaluated from leftmost to right so

When you do 8 > 7 < 6, it undergoes the steps:

8 > 7 //true
true < 6 // true, since boolean value true is 1

Similarly when you do 12 > 10 >2, it undergoes the steps:

12 > 10 //true
true > 2 //false, since boolean value true is 1

Furthermore, you cannot assume that 12 > 10 > 2 will evaluate as a whole.

edited Jul 20 '18 at 09:51

answered Jul 20 '18 at 09:07

Ankit Agarwal

@freedomn-m that is left to right – Ankit Agarwal Jul 20 '18 at 09:09
@freedomn-m ok maybe the word `rightmost ` is suitable for this. – Ankit Agarwal Jul 20 '18 at 09:11
Thanks @ankit Agarwal this really make sense :) – Rocky Jul 20 '18 at 09:13
@Rahul glad to help you – Ankit Agarwal Jul 20 '18 at 09:18
@freedomn-m Comparisons are made left to right one by one. As soon as it encounters a false... that's the end of the condition "as a whole". – Louys Patrice Bessette Jul 20 '18 at 09:19
@freedomn-m oh i got what you were saying. My bad, I was thinking other side. You are correct it is `leftmost to right`. Thanks – Ankit Agarwal Jul 20 '18 at 09:19
@LouysPatriceBessette Yes he was right. It was my typo in the answer – Ankit Agarwal Jul 20 '18 at 09:20
2

@LouysPatriceBessette: Not in comparisons. Only (some) logical conditions short-circuit at a `false`. – Cerbrus Jul 20 '18 at 09:20
@AnkitAgarwal: I also messed the logic loll.. Don't worry. ;) **Hey! That was a good question after all!** – Louys Patrice Bessette Jul 20 '18 at 09:20
Few - glad I wasn't going mad :) Conversely some operations *are* right-to-left, eg assignment `var a = b = c = 1;` == `var a = (b = (c = 1))` – freedomn-m Jul 20 '18 at 09:23
removed my comments as they no longer add anything – freedomn-m Jul 20 '18 at 09:24

score 2 · Accepted Answer · answered Jul 20 '18 at 09:24

2

As the other answers are saying, it will be evaluated from left to right so:

8 > 7 // true
true < 6 // true

But if you want the statement to read more mathematically logically you would need to split up the comparisons like:

8 > 7 && 7 < 6 //false

answered Jul 20 '18 at 09:24

Tom Dee

Nice focus on the OP deep question. ;) – Louys Patrice Bessette Jul 20 '18 at 09:36
@JohnR that works exactly the same. `12>10` is true, `true > 2` is false, so the end result is false – Tom Dee Jul 20 '18 at 09:47

3 Answers3