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 3 of 6.

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.

Rajesh said:   1 decade ago
@Muesh modi.

In step 4: When compiled as per your logic y=4||-1&&0 then first -1&&0 returns false.

And then 4||false becomes t||f returns true.

Ratan Jeet said:   10 years ago
Can anybody explain what the operator && and || does in the above program as I have never come across such expression and how it results in true or false?

Raji said:   1 decade ago
Please explain about the precedence of && and || operator and also explain the how the second and third step is executed.

Rose said:   8 years ago
I want to know clearly that -1 is assumed as true or false value at the same time how 0 is assumed as true or false value?

Anonymous said:   8 years ago
Anybody please clarify whether we consider associativity or precedence of && and || operators in such case?

Suneeta mishra said:   3 years ago
And (&&)operator should be true for all conditions and in OR (||), at least one condition should be true.
(1)

Neha said:   1 decade ago
According to this program they have considered only from left to right. There is no logic of precedence.

Mayank said:   1 decade ago
Y = T||T && F/*&& HAS HIGHER PRIORITY THEN ||*/.
Y = T||F.
Y = 1;

Pradip walghude said:   1 decade ago
&& and || are same priority precedence. It execute right to left.


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