delete the first character in a character array, But keep the wrest

[Noob Programmer]

How do i delete the first character in a character array?
I want output to be

Str = 'Hello'

After calling deletefirst

Str = 'ello'

void DeleteFirst (char S[ ])
{

	for( int i = 1; i < MAX_LENGTH; i++)
		cout << S[i];
}

i am just writing the wrest of the Array without deleting the first. how do i delete the first?

[j3Rz8vqX]

If using dynamic array:
Make an array of characters shorter than the prior by one and copy over all members other than the one expected to be deleted.

If not using dynamic array:
Shuffle all member an index prior to themselves, after the unit to be deleted is found, that is. Blank out the last spot.

[Noob Programmer]

now i must figure out how to do this

[Disch]

- line 4 initializes i to 0

- line 6 then assigns i to 0 (even though it already is zero). You probably meant == here, but even that wouldn't do much.

- line 7 is never executed because i=0 will always be 0 (false)

- line 8 is not part of your while loop because you didn't use braces. So it comes after the loop. It increments i so now i=1

- line 9 and 10 are good, and reassigns i to 1. So pretty much everything before line 9 does absolutely nothing and can be removed.

This is the same:

void DeleteFirst (char S[ ])
{
    for( int i = 1; i < MAX_LENGTH; i++)
        cout << S[i];
}

Although you can make it even simpler by printing the whole string starting with the 2nd character with some pointer math. Rather than printing it one character at a time like you are above:

void DeleteFirst (char S[ ])
{
    cout << (S+1);
}

It's also worth nothing that none of this does what the function title suggests. IE: you are not deleting the first character, you are merely printing the string passed the first character.

[Noob Programmer]

i understand. i need to copy the other parts of the character array over the one before them so the first is deleted. i am trying to figure out how. thanks for the reply

[Catfish666]

Your DeleteFirst() function doesn't look right.

You use an assignment (i = 0) as the condition instead of a comparison of some kind. This is usually a sign of a coding mistake.

In addition, i++ is outside the while() loop. This is C++, not Python. Indentation doesn't affect the meaning of the code.

Here's what you probably wanted to write:

while (i == 0)
{
    S[i] = 0;
    i++;
}

That said, your code only sets the first character to 0, and prints the string starting from the second element.

Noob Programmer wrote:

can this be simplified?

Yes, you could simply use a pointer to the second character, and print it.
(The original string will not be changed.)

char msg[] = "Hello";
const char *p = msg + 1;

std::cout << p << std::endl; // if using C++
printf("%s\n", p); // if using C 

If using C++ you are advised to use std::string instead of old fashioned char arrays.
Then you could be using std::string::substr(), among other techniques, to get a "headless" new string.
http://www.cplusplus.com/reference/string/string/substr/

If using C, you can use memmove() to copy the string onto itself.
http://www.cplusplus.com/reference/cstring/memmove/

#include <string.h>

// ...

char msg[] = "Hello";

memmove(msg, msg + 1, sizeof msg - 1);

[Noob Programmer]

Thanks for the reply,

i Changed my code to this

void DeleteFirst (char S[ ])
{

	for( int i = 1; i < MAX_LENGTH; i++)
		cout << S[i];
}

but i understand that above they mentioned i am only printing the the wrest of the Array and not really deleting the first.
Do i use Swap and switch the characters till the first becomes the last and get rid of it like Dput said? he did not mention Swap though

[j3Rz8vqX]

Example of 100% copying values:

    for(int i=0;i<i_size;i++)//Don't step out of bound(Less than max size)
    {
        i_array[i]=t_array[i];//Copy values : exactly like an array.
    }

In your case you'd want to copy everything except a selected.

Example of copying from a larger array, and excluding the "to be deleted":

    for(int i=0,j=0;i<i_size;i++,j++)//Don't step out of bound(Less than max size)
    {
        if(t_array[j]==toBeDeletedValue)
        {
            j++;//Assuming j is the larger array; this adjusts a skip for the j-indexed array;
        }
        i_array[i]=t_array[j];//Copy values : exactly like an array.
    }

In the above case, j best be larger than i or else there will be conflicts.

Hopefully the examples help.

It was modified from the browser and abstracted from another post:
http://www.cplusplus.com/forum/general/130858/