Displaying GPS coordinates on the TFT

Using Arduino Programming Questions
1

I've got a problem with displaying longitude and latitude on the Arduino TFT.
After converting the coordinates to char, the TFT only shows the first seven signs (e.g.: 4251.01).
The Rest is missing. I'm using text size 1.
Below is the code I'm using.

char latitude_c[15];
char latitude[15];
char longitude_c[15]; 
char longitude[15];
char lat_c[4];
char lat[4];
char lon_c[4];
char lon[4];///////Position

void loop()                     
{

   
    if (GPS.fix) {
  String latitude_b =String(GPS.latitude);
  latitude_b.toCharArray(latitude_c,15);// convert the reading to a char array
  String longitude_b = String(GPS.longitude);
  longitude_b.toCharArray(longitude_c,15);// convert the reading to a char array
  String lat_b = String(GPS.lat);
  lat_b.toCharArray(lat_c, 4);// convert the reading to a char array
  String lon_b = String(GPS.lon);
  lon_b.toCharArray(lon_c, 4);// convert the reading to a char array

  TFTscreen.stroke(0,0,0);
  TFTscreen.text(longitude,70,66); 
  TFTscreen.text(latitude,70,79); 
  TFTscreen.text(lon,110,66);
  TFTscreen.text(lat,110,79);
  TFTscreen.stroke(255,255,255);

      TFTscreen.text("Location:",3,53);
      TFTscreen.text("Latitude:",7,66); TFTscreen.text(latitude_c,70,66);TFTscreen.text(lat_c,135,66);
      TFTscreen.text("Longitude:",7,79); TFTscreen.text(longitude_c,70,79);TFTscreen.text(lon_c,135,79);
      
      
  latitude_b.toCharArray(latitude,15);// convert the reading to a char array
  longitude_b.toCharArray(longitude,15);// convert the reading to a char array
  lat_b.toCharArray(lat, 4);// convert the reading to a char array
  lon_b.toCharArray(lon, 4);// convert the reading to a char array

Thaks for help.

2

Below is the code I'm using.

or at least some of it.

3 
  TFTscreen.text(longitude,70,66); 
  TFTscreen.text(latitude,70,79);

You've never assigned values to these variables.

There are better ways of converting floats and ints to strings than pissing away resources on the String class. Wise up.