Replacing Characters of a string with asterix.

[eastgod]

Hello everyone,

i am relatively new to c programming, even though i have used a pc for years now and i can fix almost every issue with the normal windows pc i am very new to C programming, I lack the general logic.

Anyways i am stuck with a small problem which is say suppose i have a String like Hello, how can i hide few characters of it behind asterix?
Example String is Hello, i want the output to be like H*ell* or H**llo or what ever way.

So far i am just stuck with this:


#include<stdio.h>
#include<conio.h>
void main()
{
char s[20];
clrscr();
printf("\nEnter string : ");
gets(s);

then i am lost about the logic please help

[Salem]

SourceForge.net: Void main - cpwiki
SourceForge.net: Gets - cpwiki

Some intermediate exercises.
1. Print each char of string s individually, using a for loop and array subscripts.
2. As 1, but replace vowels with a *
3. As 2, but replace random letters with a *

[c99tutorial]

Example String is Hello, i want the output to be like H*ell* or H**llo or what ever way.

First is to nail down the requirements. If the string is "Hello", which characters should be replaced by asterisks? Then, do you want to modify the string, so that the string which formerly contained "Hello" will now contain "H**llo" or do you just want to print the string "Hello" but replacing certain characters in the output with "*"?

If you want to modify the string, here is a simple way:

s[1] = '*';
s[2] = '*';

Then if s contains "Hello", after those lines, it will contain "H**llo". Of course, this assumes that s has a strlen of at least 3 characters.

[Adak]

Welcome to the forum, eastgod!

Eastgod, you'll find we are REAL sticklers for:

1) using int main() in your program. Void main has been non-standard since dinosaurs roamed the earth.

2) using a good (you might say "godly"), indentation style. SO MANY errors are caught immediately, IF (and only if), the code has a good indentation style - where subordinate lines of code, are indented 2-5 char's.

3) always use [code] tags around your code. Otherwise the forum squishes it all out of shape, to save space and improve appearance.

Code tags are on an icon button, in the "Go Advanced" editor only. Highlight your code, click on the code tag icon, and poof! You're done.

If you want to replace a letter, that's very easy to do. If you want to ADD a * to a word, you first have to make sure that you have the room for the extra char you're adding.

Because most strings will have space for 0 extra char's to be added to them. C doesn't waste space like that.

Your example changes hello (5 chars), into h*ello (6 chars), so be careful.

One simple way to do this is to iterate over each letter, and if it's the letter you've chosen to change, change it.

int i;
char word[6]={"hello"}; //5 letters, and one space for the end of string char: '\0'
char chosenLetter='l';  //change el's

for(i=0;word[i];i++) {
   if(word[i]==chosenLetter)
      word[i]='*';
}

This is not the only way to do this task, of course.