String in function parameter

Question

int main()
{
        char *x = "HelloWorld";
        char y[] = "HelloWorld";

        x[0] = 'Z';
        //y[0] = 'M';

        return 0;
}

In the above program, HelloWorld will be in read-only section(i.e string table). x will be pointing to that read-only section, so trying to modify that values will be undefined behavior.

But y will be allocated in stack and HelloWorld will be copied to that memory. so modifying y will works fine. String literals: pointer vs. char array

Here is my Question:

In the following program, both char *arr and char arr[] causes segmentation fault if the content is modified.

void function(char arr[])
//void function(char *arr)
{
   arr[0] = 'X';
}        
int main()
{
   function("MyString");    
   return 0;
}

1. How it differs in the function parameter context?
2. No memory will be allocated for function parameters??
   

Please share your knowledge.

Answer 1

function("MyString");

is similar to

char *s = "MyString";
function(s);

"MyString" is in both cases a string literal and in both cases the string is unmodifiable.

function("MyString");

passes the address of a string literal to function as an argument.