Sending GPS location error

We're working on a project which one of its function is to send gps location through sms. We're using this Sim808 GPS GSM Module – Sending Gps Location SMS | alselectro as a basis. Everything works fine at first but after the first message instead of sending correct coordinates, it just add the new coordinate to the old one. Please help and Thank you so much
We're using arduino uno and sim808
The attached file is the output we get, it's the same for when we run the serial monitor. Thank you so much

#include <SoftwareSerial.h>
SoftwareSerial sim808(7,8);

char phone_no[] = "09056647398"; // replace with your phone no.
String data[5];
#define DEBUG true
String state,timegps,latitude,longitude;

void setup() {
 sim808.begin(9600);
 Serial.begin(9600);
 delay(50);

 sim808.print("AT+CSMP=17,167,0,0");  // set this parameter if empty SMS received
 delay(100);
 sim808.print("AT+CMGF=1\r"); 
 delay(400);

 sendData("AT+CGNSPWR=1",1000,DEBUG);
 delay(50);
 sendData("AT+CGNSSEQ=RMC",1000,DEBUG);
 delay(150);
 
}

void loop() {
  sendTabData("AT+CGNSINF",1000,DEBUG);
  if (state !=0) {
    Serial.println("State  :"+state);
    Serial.println("Time  :"+timegps);
    Serial.println("Latitude  :17.635343"+latitude);
    Serial.println("Longitude  :121.742960"+longitude);

    sim808.print("AT+CMGS=\"");
    sim808.print(phone_no);
    sim808.println("\"");
    
    delay(300);

    sim808.print("http://maps.google.com/maps?q=loc:");
    sim808.print("17.635343");
    sim808.print(",");
    sim808.print ("121.742960");
    delay(200);
    sim808.println((char)26); // End AT command with a ^Z, ASCII code 26
    delay(200);
    sim808.println();
    delay(20000);
    sim808.flush();
    
  } else {
    Serial.println("GPS Initialising...");
  }
}

void sendTabData(String command , const int timeout , boolean debug){

  sim808.println(command);
  long int time = millis();
  int i = 0;

  while((time+timeout) > millis()){
    while(sim808.available()){
      char c = sim808.read();
      if (c != ',') {
         data[i] +=c;
         delay(100);
      } else {
        i++;  
      }
      if (i == 5) {
        delay(100);
        goto exitL;
      }
    }
  }exitL:
  if (debug) {
    state = data[1];
    timegps = data[2];
    latitude = data[3];
    longitude =data[4];  
  }
}
String sendData (String command , const int timeout ,boolean debug){
  String response = "";
  sim808.println(command);
  long int time = millis();
  int i = 0;

  while ( (time+timeout ) > millis()){
    while (sim808.available()){
      char c = sim808.read();
      response +=c;
    }
  }
  if (debug) {
     Serial.print(response);
     }
     return response;
}

it just add the new coordinate to the old one

The data String is never set back to "" after sending the message. Do you see how that might cause a problem ?

UKHeliBob:
The data String is never set back to "" after sending the message. Do you see how that might cause a problem ?

Yes, but we tried to set it back to no value or null but it didn't work. Can you suggest we're it's best to put that code? Thank you for responding

we tried to set it back to no value or null but it didn't work

Post what you tried

Can you suggest we're it's best to put that code?

after you send the data would seem to be logical