This function returns whether a font with the specified index exists or not. Please note, that the value used for checking must have been initialised previously or else you will get an error causing GameMaker Studio 2 to close.
font_exists(ind);
Argument Description ind Index of the font to check.
Boolean
if font_exists(fnt_Main)
{
draw_set_font(fnt_Main);
}
This will set the active drawing font to fnt_Main if it exists.