C Programming - Expressions - Discussion

Discussion Forum : Expressions - Find Output of Program (Q.No. 6)
6.
What will be the output of the program?
#include<stdio.h>
int main()
{
    int i=4, j=-1, k=0, w, x, y, z;
    w = i || j || k;
    x = i && j && k;
    y = i || j &&k;
    z = i && j || k;
    printf("%d, %d, %d, %d\n", w, x, y, z);
    return 0;
}
1, 1, 1, 1
1, 1, 0, 1
1, 0, 0, 1
1, 0, 1, 1
Answer: Option
Explanation:

Step 1: int i=4, j=-1, k=0, w, x, y, z; here variable i, j, k, w, x, y, z are declared as an integer type and the variable i, j, k are initialized to 4, -1, 0 respectively.

Step 2: w = i || j || k; becomes w = 4 || -1 || 0;. Hence it returns TRUE. So, w=1

Step 3: x = i && j && k; becomes x = 4 && -1 && 0; Hence it returns FALSE. So, x=0

Step 4: y = i || j &&k; becomes y = 4 || -1 && 0; Hence it returns TRUE. So, y=1

Step 5: z = i && j || k; becomes z = 4 && -1 || 0; Hence it returns TRUE. So, z=1.

Step 6: printf("%d, %d, %d, %d\n", w, x, y, z); Hence the output is "1, 0, 1, 1".

Discussion:
51 comments Page 4 of 6.

Rohit Maru said:   1 decade ago
Priority of logical and (&&) is more than logical or (||).

Rohit said:   1 decade ago
Is there any priority in solving?

Bharadwaj said:   1 decade ago
In step 4, how the y value become true. i.e 4 || -1 && 0. How it results true.

4 || -1 is true and true && 0 means false. But it is returning true. Why?

Plz clarify my doubt

Wikiok said:   1 decade ago
As Rohit Maru said: && has higher priority than ||. So left-to-right associativity can not be used.
Step 4:
1st substep: "-1 && 0" --> False
2nd substep: "4 || False" --> True
So the answer is True, so it is "1".

Pallavi said:   1 decade ago
Can anyone explain step3 and step5 please ?

Richa goel said:   1 decade ago
Since the peccedence of && operator is more than the preccedence of || operator
so, (j&&k) is solved first in step 4 .
hence the ans true.
and similarly in step 5.

Richa said:   1 decade ago
Please explain the precedence and associativity of these operator.

Monika said:   1 decade ago
Can anyone please tell the operation of && and ! operators.

Pooja said:   1 decade ago
@ Wikiok and Richa

Can you please explain me that if the precedence of && operator is more than ||operator then in the explanation of question no 3(previous page) it was written that

"Step 2: m = ++i || ++j && ++k; here (++j && ++k;) this code will not get executed because ++i has non-zero value.
becomes m = -2 || ++j && ++k;
becomes m = TRUE || ++j && ++k; Hence this statement becomes TRUE. So it returns '1'(one). Hence m=1."

From this we can understand that it is evaluated from left.
Can anyone clear my doubt please please??

Sahithi said:   2 decades ago
Please give clear explanation.


Post your comments here:

Your comments will be displayed after verification.