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;
}
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 2 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.
so, (j&&k) is solved first in step 4 .
hence the ans true.
and similarly in step 5.
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??
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??
Vicky kumar said:
1 decade ago
In step 4 the answer should be false but Wikiok said the right answer is true. It can't be happen because logical 'and' or 'or'.
Operator have left to right precedency.
But you are saying right to left how it is possible.
Please give me details.
Operator have left to right precedency.
But you are saying right to left how it is possible.
Please give me details.
Geetha said:
1 decade ago
In step 4 how that answer will come. Please give me explanation.
Purnima said:
1 decade ago
Step 1: i = 4, j = -1, k = 0
Take all values which are greater than or equal to zero as TRUE(T) and which are less than zero as FALSE(F).
Step 2: w = i || j || k
= 4 || -1 || 0
= (T || F) || T
= T || T = T
w = 1
Similarly we get all the expression. Check it out.
Take all values which are greater than or equal to zero as TRUE(T) and which are less than zero as FALSE(F).
Step 2: w = i || j || k
= 4 || -1 || 0
= (T || F) || T
= T || T = T
w = 1
Similarly we get all the expression. Check it out.
Sunitha said:
1 decade ago
@Purnima once check out your logic friend.except zero all the numbers are true.
And friend @Vicky kumar here the logical operators have left to right priority but When more than one logical operator is used in a statement, NOT is evaluated first, then AND, and finally OR)
i=4, j=-1, k=0
Here in statement z = i && j || k
= 4 && -1|| 0
= T && T || F
= T
= T || F
= T
AND FINALLY RETURNS 1. AS 1 INDICATES TRUE
And friend @Vicky kumar here the logical operators have left to right priority but When more than one logical operator is used in a statement, NOT is evaluated first, then AND, and finally OR)
i=4, j=-1, k=0
Here in statement z = i && j || k
= 4 && -1|| 0
= T && T || F
= T
= T || F
= T
AND FINALLY RETURNS 1. AS 1 INDICATES TRUE
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.
Udaya said:
1 decade ago
I think the Logic is like whenever they got OR operator they are not going for further expression as OR operator will return 1 of one operand is 1. And if the operator is && they were executing the whole expression.
Pradip walghude said:
1 decade ago
&& and || are same priority precedence. It execute right to left.
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