C Programming - Arrays - Discussion

Discussion Forum : Arrays - Find Output of Program (Q.No. 1)
1.
What will be the output of the program ?
#include<stdio.h>

int main()
{
    int a[5] = {5, 1, 15, 20, 25};
    int i, j, m;
    i = ++a[1];
    j = a[1]++;
    m = a[i++];
    printf("%d, %d, %d", i, j, m);
    return 0;
}
2, 1, 15
1, 2, 5
3, 2, 15
2, 3, 20
Answer: Option
Explanation:

Step 1: int a[5] = {5, 1, 15, 20, 25}; The variable arr is declared as an integer array with a size of 5 and it is initialized to

a[0] = 5, a[1] = 1, a[2] = 15, a[3] = 20, a[4] = 25 .

Step 2: int i, j, m; The variable i,j,m are declared as an integer type.

Step 3: i = ++a[1]; becomes i = ++1; Hence i = 2 and a[1] = 2

Step 4: j = a[1]++; becomes j = 2++; Hence j = 2 and a[1] = 3.

Step 5: m = a[i++]; becomes m = a[2]; Hence m = 15 and i is incremented by 1(i++ means 2++ so i=3)

Step 6: printf("%d, %d, %d", i, j, m); It prints the value of the variables i, j, m

Hence the output of the program is 3, 2, 15

Discussion:
39 comments Page 2 of 4.

Priya said:   1 decade ago
The order of printf function is i, j, k. Then it o/p is 2 3 15.

OMNARAYAN TIWARI said:   10 years ago
The value of m=a[i++] not clear and its output is also confusing. It seems it's giving the output of j, i, m.

Manasa said:   9 years ago
Why i value is 3?

Venkatesh said:   8 years ago
int a[5]={75,94,123,566,334};
instead of that given array use this.

Mayank said:   8 years ago
Hi,

++a[1] can we written as ++ *(a+1); (associativity right to left)
as *(a+1)=1;
++1; should give error.
But it works why?

Yogita sable said:   7 years ago
I don't understand please can you explain it again?

Anita said:   7 years ago
Please explain it to me to understand the concept of this.

Mehul said:   1 decade ago
Now i am getting it
see
a[i++] is definately pointing to 15 hence printed

but NOTICE THAT i++ is there hence i=i+1 too keep in your mind .
i=2+1 ==3
hence 3,2,15

Mainak said:   6 years ago
I am not understanding step 5. Please explain it clearly.

Rosh said:   5 years ago
@Mohanapriya @Rupinderjit Singh

It was quit understandable explanation but still, I have a doubt j and m both are using post increment then why only m is incremented (when we reach to print statement ). Why not j?

Please explain about it.


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