Chaining of Relational operators is giving wrong output [closed]

Answer 1

In your code, what you've tried

 else if(18.5<=bmi<23)

No, this kind of chaining of Relational operators is not possible in C. You should write

 else if((18.5<=bmi) &&  (bmi < 23))

to check bmi value in [18.5, 23) and so on for the other cases.

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EDIT:

Just to elaborate about the issue, an expression like

18.5<=bmi<23

is perfectly valid C syntax. However, it is essentially the same as

((18.5<=bmi) < 23 )

due to the operator associativity.

So, first the (18.5<=bmi) is evaluated and the result , (0 or 1) gets to get comapred against 23, which is certainly not you want here.

Answer 2

This:

18.5<=bmi<23

means the same as

(18.5 <= bmi) < 23

In other words the value of bmi is never compared to 23. You must not use that kind of math-syntax in C, it should be written as:

(18.5 <= bmi) && (bmi < 23)

So it's really two comparisons of the variable, and must be written using the boolean-and (&&) operator to make this explicit.

Answer 3

Yes, C language does show you the right answer of what you've tried.

There is no syntax like this in C for comparison (but yes, it's a valid syntax):

else if(18.5<=bmi<23)

it should be this:

else if((18.5<=bmi)&&(bmi < 23))