C Programming - Pointers - Discussion
Discussion Forum : Pointers - Find Output of Program (Q.No. 22)
22.
What will be the output of the program ?
#include<stdio.h>
int main()
{
int i, a[] = {2, 4, 6, 8, 10};
change(a, 5);
for(i=0; i<=4; i++)
printf("%d, ", a[i]);
return 0;
}
void change(int *b, int n)
{
int i;
for(i=0; i<n; i++)
*(b+1) = *(b+i)+5;
}
Discussion:
52 comments Page 5 of 6.
Surendra said:
1 decade ago
@Ramya
a[] = {2, 4, 6, 8, 10}
If you observe the line *(b+1)=*(b+i)+5;
it clearly tells that they want to change the second element.
secondly every time in the loop they are assinging a new value to it.
for i=0; *(b+i) is 2 and +5 equals 7
for i=1; *(b+i) is 7 and +5 equals 12
for i=2; *(b+i) is 6 and +5 equals 11
for i=3; *(b+i) is 8 and +5 equals 13
for i=4; *(b+i) is 10 and +5 equals 15
a[] = {2, 4, 6, 8, 10}
If you observe the line *(b+1)=*(b+i)+5;
it clearly tells that they want to change the second element.
secondly every time in the loop they are assinging a new value to it.
for i=0; *(b+i) is 2 and +5 equals 7
for i=1; *(b+i) is 7 and +5 equals 12
for i=2; *(b+i) is 6 and +5 equals 11
for i=3; *(b+i) is 8 and +5 equals 13
for i=4; *(b+i) is 10 and +5 equals 15
Gowthami said:
1 decade ago
Thanku surendra and Atul.
@ashwini said:
1 decade ago
Hey guys i din understand... confused...
If after computin *(b+1)=*(b+i)+5;
we get 7,12,11,13,15
then how cum is OPTION B the answer...
Please help m out!!
If after computin *(b+1)=*(b+i)+5;
we get 7,12,11,13,15
then how cum is OPTION B the answer...
Please help m out!!
Abi said:
1 decade ago
I can't understand how the answer is option b? someone explains if you knows.
Sun said:
1 decade ago
When we Run this program will get the answer B.
How is it ? any one can explain. ?
How is it ? any one can explain. ?
Loknath said:
1 decade ago
Hello friends
*(b+1)=b[1];
for(i=0;i<n;i++)
b[1]=b[i]+5;
//at last b[1]=2+5......at last b[1]=10+5;
then store in address b[1]=15
ok good day
*(b+1)=b[1];
for(i=0;i<n;i++)
b[1]=b[i]+5;
//at last b[1]=2+5......at last b[1]=10+5;
then store in address b[1]=15
ok good day
Karthik said:
1 decade ago
for(i=0; i<n; i++)2, 4, 6, 8, 10};
*(b+1) = *(b+i)+5;
In this for loop,only (b+1) location value is updated but not entire array
i.e 1st iteration (b+1)=(b+0)+5<=>2+5=7
2nd iteration (b+1)=(b+1)+5<=>4+5=9
after 5 iterations, the final value that is in (b+1) is
*(b+1)=*(b+4)+5<=>10+5=15;
change() will return an array *b whose *(b+1) location is updated by 15 Hence array a[] will hold values 2,15,6,8,10. since array a[] is passed into array b[](using pass-by-address) hence any changes made in b[] will reflect back in array a[].
*(b+1) = *(b+i)+5;
In this for loop,only (b+1) location value is updated but not entire array
i.e 1st iteration (b+1)=(b+0)+5<=>2+5=7
2nd iteration (b+1)=(b+1)+5<=>4+5=9
after 5 iterations, the final value that is in (b+1) is
*(b+1)=*(b+4)+5<=>10+5=15;
change() will return an array *b whose *(b+1) location is updated by 15 Hence array a[] will hold values 2,15,6,8,10. since array a[] is passed into array b[](using pass-by-address) hence any changes made in b[] will reflect back in array a[].
Thomsika said:
1 decade ago
Can anyone explain me the concept clearly. I could not understand. What is the value of b?
Jyoti Nagpal said:
1 decade ago
Only a[1] value is changed. Reaming arrays value are same,
*(b+1) = *(b+i)+5;
b is base address +1 means assign the value to b[1];
Every time, each row is increment by 5 and assign to b[1].
At last value increment with five and finally overwrite value 10+5=15.
*(b+1) = *(b+i)+5;
b is base address +1 means assign the value to b[1];
Every time, each row is increment by 5 and assign to b[1].
At last value increment with five and finally overwrite value 10+5=15.
Prithviraj said:
1 decade ago
Answer is [B]. 2, 15, 6, 8, 10.
Because in the above code there are few mistakes.
1) There is no link between main program and function. i.e there is no prototype.
2) Return type is void.
Because in the above code there are few mistakes.
1) There is no link between main program and function. i.e there is no prototype.
2) Return type is void.
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