strlen function help

[aadil7]

hello
im just confused even after some reading of how to write the strlen function
i dont want to call it from the string library

here's how far ive got so far

#include <stdio.h>
#include "simpleio.h"

int strlen(char *myString)
{
	
	return 0;
}

int main()
{
	char myNum[256];
	int x;
	int i;

	printf("enter the numbers: \n");
	getString(myNum,255);

	x = strlen(myNum);
	for(i=x-1;i>=0;i--)
	{
		printf("%c \n", myNum[i]);
	}
	return 0;
}

[Sebastiani]

Run through 'myString' until you encounter a zero. The two most common approaches are to either increment a counter inside the loop or else subtract the start address with the address of the last character (the null terminator, that is) to obtain the length.

[aadil7]

i just dont know how i should program this
the logic is simple

a basic structure on how it should be done just to give me a step would be appreciated

[Tool]

int strlen(char *myString)
{
        int len = 0;
	char *p = myString;
        while(*p)
             len++, p++;
	return len;
}

[aadil7]

thanks loads that did the job

i think i just need to learn how to break functions down on a further level
thanks again

[Sebastiani]

int strlen(char *myString)
{
        int len = 0;
    char *p = myString;
        while(*p)
             len++, p++;
    return len;
}

That's very generous of you, but then how is anyone to learn anything if we do all of their fishing for them? Give advice, pseudocode, and tips...not the entire solution!

[quzah]

Tip #1: recursion is fun.

int mystrlen( char *s )
{
    return s && *s ? 1 + mystrlen( s + 1 ) : 0;
}

Quzah.

[Feengur]

aadil7,

How about since tool just did the task for you, why don't you breakdown the (short) function Tool wrote for you and explain it to us?

If you really want to learn it'll do you good.

-Feen

[mywaylgh]

int strlen(char *myString)
{
	int len=0;
	while(myString[len]!='\0')
		len++;
	return len;
}

[quzah]

int mystrlen( char *s )
{
    char *p = s;
    while( p && *p )
        p++;
    return p - s;
}

Quzah.

[claudiu]

As someone once said give people fishing rods not fish itself!

[quzah]

If someone has already given them a fish, why does it hurt to give them another one? Especially if it's a fish they don't know how to clean when asked. Or something.


Quzah.

[GReaper]

Tip #1: recursion is fun.

int mystrlen( char *s )
{
    return s && *s ? 1 + mystrlen( s + 1 ) : 0;
}

Quzah.

It is much slower too!

[quzah]

It is much slower too!

I didn't write it because it was the optimal solution. I wrote it because... wait a minute, didn't I already explain this? Go read Tip #1 again.


Quzah.

[aadil7]

aadil7,

How about since tool just did the task for you, why don't you breakdown the (short) function Tool wrote for you and explain it to us?

If you really want to learn it'll do you good.

-Feen

i do understand the coding
its just that im still new to the whole programming side of things, so i didn't know how to actually phrase things together. but im working on C alot more now so hopefully it will click sooner rather than later.

and heres what it means:

int strlen(char *myString)
{
int len = 0; /*make an integer called len and set it to 0*/
char *p = myString; /*p is a pointer to myString*/
while(*p) /*while loop stating while p is still pointing to a character increment len and p so it moves across to the next character*/
len++, p++;
return len; /*len has been counting how many characters have been noted*/
}