C++ How do I delete a certan character in a string?

Question

Hello so I'm basically trying to do something like this.

PrintOpt("Hello | I | Am | Awesome");

and in my PrintOpt code

void PrintOpt(char* Text){
     if(!strcmp(Text, " | ")){
           Text = "\n";
     }
     printf(Text);
}

I would like it to print out like this

Hello
I
Am
Awesome
(On a new line)

But when I do this it doesn't print out anything. Does anyone know why this isn't working? Thank you

Do you mean you want every word on its own line? I.e. every instance of `|` is replaced with `\n`? — BoBTFish, Feb 05 '15 at 21:37
Why are you using C-style strings in a C++ program? You're likely just to get a big pile of answers saying "use std::string". — Carl Norum, Feb 05 '15 at 21:41
Dude, this is C code, not C++. I would suggest taking a step back and reading up on string and pointers. — OldProgrammer, Feb 05 '15 at 21:41
Sorry, I'm just a beginner at this. I don't really know the difference. — Ambition, Feb 05 '15 at 21:43
possible duplicate of [Split a string in C++?](http://stackoverflow.com/questions/236129/split-a-string-in-c) — Don Larynx, Feb 05 '15 at 21:43
Right now you're passing the address of a string literal. Attempting to modify the content of that string literal will give undefined behavior, so most of the advice about *how* to do this will almost inevitably fail until/unless you pass something that can be modified safely. — Jerry Coffin, Feb 05 '15 at 21:44

score 5 · Answer 1 · answered Feb 05 '15 at 21:41

5

Use the std::string replace method

answered Feb 05 '15 at 21:41

Marcus Müller

34,677
4
53
94

score 2 · Answer 2 · answered Feb 05 '15 at 21:45

2

First of all you should not pass string literal "" as char * and especially try to modify that data. Use std::string instead:

void PrintOpt(std::string Text){
     while( true ) {
         size_t pos = Text.find( " | " );
         if( pos == std::string::npos ) break;
         Text = Text.replace( pos, 3, "\n" );
     }
     std::cout << Text;
     // or printf(Text.c_str()); if you insist on printf()
}

answered Feb 05 '15 at 21:45

Slava

43,454
1
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90

Almost exactly what I was about to post. Although I did the `find` and check against `npos` in the `while` condition. – BoBTFish Feb 05 '15 at 21:48

score 0 · Answer 3 · answered Feb 05 '15 at 21:41

In the statement "if(!strcmp(Text, " | ")) you get a false. Then you make the variable Text take the value "\n" and you print it (\n is the equivalent of a new line). I guess that's why it doesn't work as expected.

To replace characters you could use the function std::replace.

score 0 · Answer 4 · answered Feb 05 '15 at 21:44

0

I think you must use strcmp on the every character of string and not all of it at once.

answered Feb 05 '15 at 21:44

Coldblue

144
2
8

C++ How do I delete a certan character in a string?

4 Answers4