Apps picks junk value after the string clear() calls

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#include<iostream>
#include<stdio.h>
#include<string.h>
#include<string>
#include<algorithm>
using namespace std;

typedef struct math
{
   string a;
   string b;
   int c;

   math()
   {
      c = 1000;
      printf("c = %d\n", c);
   }

}m3;

void print(struct math m1)
{
   cout<<"a : "<<m1.a<<endl;
   cout<<"b : "<<m1.b<<endl;
   cout<<"c : "<<m1.c<<endl;
}

void my_func(struct math &m1)
{
   m1.a.clear();
   m1.a = '\0';
   m1.b.clear();
   m1.b = '\0';
   m1.c = 0;
}

int main()
{
   math m1;
   m1.a = "OPEN";
   m1.b = "close";
   m1.c = 20;

   print(m1);

   my_func(m1);

   print(m1);

}

like same portion am using in application but am getting junk value after the

my_func

calls. how to restrict this type of case or any other method helps me????

What I have tried:

analysis are done but no use of it. help me if u can.

Posted 6-Mar-23 22:48pm

mathiv327

Updated 7-Mar-23 0:39am

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Comments

Richard MacCutchan 7-Mar-23 6:35am

I just tried your code and it works fine. Which compiler are you using?

Richard MacCutchan 7-Mar-23 6:41am

You do not need a null character in a STL string type, as it controls the content by keeping a count of the contents. Placing the null character there just makes it a string with a length of 1 character.

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CPallini · Answer 1 · 2023-03-07T00:39:00

Solution 1

Your code produces the expected output (no junk) on my linux box:

c = 1000
a : OPEN
b : close
c : 20
a : 
b : 
c : 0

Note, I think you need neither

Quote:
m1.a = '\0';

nor

Quote:
m1.b = '\0';

In any case, you should use the debugger in order to see what happens on your system.

Posted 7-Mar-23 0:39am

CPallini