Mock test Gate2018 testbook

Question

How to perform string and char operation in programming ? Please explain and also provide the solution

Comments

Segmentation fault because it attempts to access next memory location after go string.

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Can anyone please explain in detail?

Answer 1

go points to "yolo"

1- go+2 will point to l, "%s" will print= lo;

2- ++go will make go=go+1;  go will now point to o- "%s" prints olo;

2- According to Dennis Ritchie's book ( who created c programming language) - an array of characters and pointer to string constant both are different,

char g[]="now is the time"; //an array of characters

char *g="now is the time"; //a pointer to sting constant

individual characters within an array can be changed  but g will always going to point to same storage. On the other hand, the pointer g may subsequently be modified to point somewhere else, but the result is undefined if you try to modify the string contents.

now coming back to question

++go[1] = ++(go[1])  // [] has higher priority than ++ operator

go[1] points to l ; // note- go was incremented previously

but ++(go[1]) is changing string contents hence segmentation fault is there.

Answer 2

https://www.geeksforgeeks.org/whats-difference-between-char-s-and-char-s-in-c/ 

read this it may help

Answer 3

Here, go is not an array but string literals.So, we cannot access their element like an array. Here, go array does not exist but you try to access them so it gives segmentation fault.