Seg Fault After Setting Up New Public Signal in QT - qt

Question

I am just getting my feet wet with Qt, I am trying to pull the string from a QlineEdit and append it to a QTextBrowser after clicking a button(for simplicity/error checking I am just having it append the word appended at the moment).
The program runs, and the GUI gets brought up on the screen, but whenever I click the button, my program seg faults.
Here's my code, I cut a lot out that was unnecessary:
HEADER:
#ifndef TCD2_GUI_H
#define TCD2_GUI_H
//bunch of includes
class TCD2_GUI : public QWidget
{
Q_OBJECT
public:
TCD2_GUI(QWidget *window = 0);
//bunch of other members
QLineEdit *a1_1;
QTextBrowser *stdoutput;
public slots:
void applySettings(void);
private:
};
#endif // TCD2_GUI_H
and here is the snippet of the cpp of which causes the fault
QTextBrowser *stdoutput = new QTextBrowser();
stdoutput->append("Welcome!");
QObject::connect(apply, SIGNAL(clicked()), this, SLOT(applySettings()));
//------------------------------------------------------Standard Output END
//layout things
}
void TCD2_GUI::applySettings()
{
stdoutput->append("appended");
}

Answer 1

stdoutput in your applySettings() function refer to the member of the TCD2_GUI class whereas stdoutput in your piece of code where the crash happens is a local variable.
Try to add in your constructor by example:
stdoutput = new QTextBrowser();
andremove the following line from your piece of code:
QTextBrowser stdoutput = new QTextBrowser();

Answer 2

looking at the code provided, my guess would be stdoutput is declared twice. Once as a member of the *TCD2_GUI* class, second time as a local variable in the method (class constructor?) where you do layout. ApplySettings uses a class member which is not initialized, hence segmentation fault.
Changing your code to:
stdoutput = new QTextBrowser();
stdoutput->append("Welcome!");
QObject::connect(apply, SIGNAL(clicked()), this, SLOT(applySettings()));
might fix the problem.
hope this helps, regards