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How to clear a string

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How to clear a string

Aug 27th, 2007

How do you clear a string in a single statement ?
for egs. i want to clear name[20] of all its contents and leave it completely empty

Please help

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Re: How to clear a string

Aug 27th, 2007

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Originally Posted by joydsouza90

How do you clear a string in a single statement ?
for egs. i want to clear name[20] of all its contents and leave it completely empty

Please help

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
  const char *str="SpS";
  cout << str;
  str = NULL;
  const char *str="SpS";
  cout << str;
  str = NULL;

Last edited by SpS; Aug 27th, 2007 at 12:24 pm.

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Re: How to clear a string

Aug 27th, 2007

It's a character string? Just set the first character to be a terminator and it'll be treated as "".

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
name[0] = '\0';
name[0] = '\0';

If it's a C++ string you can call the clear method and that truncates the string to be "".

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
name.clear();
name.clear();

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Re: How to clear a string

Aug 27th, 2007

Are you talking about C++ strings or C-style char arrays? (I assume you're talking about char arrays, based on your post)

What do you mean by "completely empty"?

You can make a C++ string blank by doing this

 Help with Code Tags 
 CPP Syntax (Toggle Plain Text) 
std::string name = "hello";
std::cout << name;
 
//Assign 'name' a blank string
name = ""; 
std::cout << name;
std::string name = "hello";
std::cout << name;

//Assign 'name' a blank string
name = ""; 
std::cout << name;

for a C-style char array, you could do this

 Help with Code Tags 
 CPP Syntax (Toggle Plain Text) 
char name[20] = "fred";
std::cout << name;
 
//If the first character is a null terminator, the string is 'empty'.
name[0] = '\0' ;
std::cout << name;
char name[20] = "fred";
std::cout << name;

//If the first character is a null terminator, the string is 'empty'.
name[0] = '\0' ;
std::cout << name;

Or do you wish to iterate through every element and set each one to zero? (You can do that with a loop, although there's not much point.)

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Re: How to clear a string

Aug 27th, 2007

im using turbo c++
and none of the methods that u guys have mentioned seem to work

name[20] is a character array

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Re: How to clear a string

Aug 27th, 2007

Please post the code you have so far...

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Hamrick

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Re: How to clear a string

Aug 27th, 2007

Okay then, what are you doing exactly?

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Re: How to clear a string

Aug 27th, 2007

•

Originally Posted by joydsouza90

How do you clear a string in a single statement ?
for egs. i want to clear name[20] of all its contents and leave it completely empty

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
   char name[20];
   memset(name, 0, sizeof name);
   char name[20];
   memset(name, 0, sizeof name);

Although typically clearing all elements of a string is unnecessary.

"One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand

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Re: How to clear a string

Aug 27th, 2007

thanx a lot !!!

memset works .

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iamthwee

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Re: How to clear a string

#10

Aug 27th, 2007

You should have posted the code for the others you have tried and the error messages or problems you encountered. The problem is unlikely to be with their code but rather how you typed it in or if you're using the outdated version of turbo c, which is probably very likely