Hanging when working with basic types in Qt

[tomy]

In a program, I want to display the number 0.12345 as .12345 (removing the first zero) in a lineEdit. For this I wrote the simple code below:

QString s;
QTextStream ss(&s);

  double temp = 0.12345;
  int n = 0;

 if(temp > 0)
    {
      ss << ".";
     while(true)
       {
         temp *= 10;
         n = temp;
         if(temp == n)
             break;
       }
     ss << n;
  }

 lineEdit-> setText(s);

When I run the it, the compiler (Qt Creator) hangs and I need to rerun the code to normally go out of it.

What is the problem that the compiler acts that way, please, and how to solve it?

[koahnig]

@tomy

You programmed an endless loop!

Not the compiler nor Qt creator hangs. Your application sucks the whole computation power until it crashes.
You are comparing a double with an integer. The integer gots converted to a double, but because of the conversion both numbers are never the same and your break is never triggered.

Probably something like the following may work

 while(true)
{
         temp *= 10;
         n = temp;
         if( fabs ( temp -n) < 0.000001 )
             break;
}

[koahnig]

A bit of description of the problem you are having you can find after the first headline Comparing for equality

[nestorac]

We can't compare a double to an int. Anyways, I find the "break;" disturbing. I don't feel comfortable with it. I would try to remake this code.