Unable to access all elements of Array Structure

Question

I am coding a GUI for my menu. The problem is this that when I access the drawtext function only the first element of my sub_menu char array is getting displayed when I access the function using

        drawText(38,195,*a->sub_Menu[1],0);
        drawText(38,240, a->sub_Menu[2],0);
        drawText(38,285, a->sub_Menu[3],0);
        drawText(38,330, a->sub_Menu[4],0);

and rest of the boxes show up blank. And when I try to access the drawtext funcion using

        drawText(38,195,*a->sub_Menu[1],0);
        drawText(38,240,*a->sub_Menu[2],0);
        drawText(38,285,*a->sub_Menu[3],0);
        drawText(38,330,*a->sub_Menu[4],0);

the program compiles and runs but as soon as I click on Settings button of my menu the program crashes saying myprogram.exe has stopped working. I don't know what the problem is as I am new to coding.

    typedef struct {
    short startXPos;
    short startYPos;
    short height;
    short width;
    unsigned int c;
    char *sub_Menu[5][18];
} menu, *ptr_Menu;

ptr_Menu a;
char sub_Menu1[5][18] = {"Big Font", "5 channel", "7 channel", "12 channel", "Alarm"};
menu touch_menu[10] = {30, 365, 45, 100, 5, &sub_Menu1};

void drawMenu(short b)
{
    int k = 0;
    if (b == 0) {
        a = &touch_menu[0];
        for (k=0; k<a->c; k++) {
            setColor(GREY);
            drawRectangle(a->startXPos, a->startYPos - (k+1)*a->height,a->width,a->height);
        }
        setColor(CYAN);
        drawText(38,150,*a->sub_Menu[0],0);
        drawText(38,195,*a->sub_Menu[1],0);
        drawText(38,240,*a->sub_Menu[2],0);
        drawText(38,285,*a->sub_Menu[3],0);
        drawText(38,330,*a->sub_Menu[4],0);
    }
}

Answer 1

Your problem is that you think

char *sub_Menu[5][18];

is a pointer to a 5x18 character array. But in reality it's a 5x18 array of char pointers.

Change your struct type like this:

char *sub_Menu[5];

And the initialization:

menu touch_menu[10] = {
    { 30, 365, 45, 100, 5, { "Big Font", "5 channel", "7 channel", "12 channel", "Alarm" } },
    // remaining 9 menu data comes here
};

And drawing the text. You'd be better off with a loop. DRY (Don't Repeat Yourself).

drawText(38, 240, a->sub_Menu[2], 0);

The strings are stored in the constant area of your program, they contain a terminating zero, so you don't have to worry about their length (18). All you need is an array of 5 character pointers in your struct.

As to the initializer, it needs 3 levels of nested {} symbols:

• 1st level because touch_menu is an array
• 2nd level because it contains structs
• 3rd level because each struct contains an array