How to print on lcd or serial variable that is used in library cpp file?

Hi i made a library for pressure sensor and all calculations are made in cpp file , and so i want to print the result on serial or lcd but i can't accsess the result in cpp file.
Here is ardu code :

#include <MS5803.h>
#include <Wire.h>
#include <LiquidCrystal.h>

MS5803 sensor =  MS5803();
LiquidCrystal lcd(12,11,5,4,3,2);

void setup() {
  Wire.begin();
  lcd.begin(16, 2);
  sensor.resetsensor();
  sensor.readcalib();
  delay(10);

}

void loop() {

  sensor.readT();
  delay(100);
  sensor.calcT();
  delay(30);
  lcd.setCursor(0, 0);
  lcd.println(Temperature); // I want to print that value on LCD
  delay(1000);
}

And here is my MS5803.h :

#ifndef MS5803_H
#define MS5803_H


#include "Arduino.h"



class MS5803 
{
public:
    MS5803();  
    void resetsensor();
	void readcalib();
	void readP();
	void readT();	
	void calcP();
	void calcT();
	
private:
		
};

#endif

and MS5803.cpp :

#include "MS5803.h"
#include "Arduino.h"
#include <Wire.h>

#define Reset  		0x1E
#define D1_256 		0x40
#define D1_512  	0x42
#define D1_1024  	0x44
#define D1_2048  	0x46
#define D1_4096  	0x48
#define D2_256  	0x50
#define D2_512  	0x52
#define D2_1024  	0x54
#define D2_2048  	0x56
#define D2_4096  	0x58
#define AdcRead  	0x00
#define PromBaseAddress  0xA0
#define Address 0x77

		 unsigned int CalConstant[8];  
		 long AdcTemperature, AdcPressure = 0; //RAW ADC data
	     float  Temperature,Pressure,TempDifference, Offset, Sensitivity = 0;
		 float T2, Off2, Sens2 = 0; 
		 byte ByteHigh, ByteMiddle, ByteLow;  // Variables for I2C reads


MS5803::MS5803() {
}

void MS5803::resetsensor() {	
	Wire.beginTransmission(Address);
	Wire.write(Reset);
	delay(10);
	Wire.endTransmission();	
	}
	
void MS5803::readcalib() {
	 for (byte i = 0; i < 8; i++)
  {
    Wire.beginTransmission(Address); 
    Wire.write(PromBaseAddress + (2*i));
    Wire.requestFrom(Address, 2);
    while(Wire.available()){
      ByteHigh = Wire.read();
      ByteLow = Wire.read();
    }
    CalConstant[i] = (((unsigned int)ByteHigh << 8) + ByteLow);
   }
  }
  
void MS5803::readP() {

  Wire.beginTransmission(Address);
  Wire.write(D1_1024);
  delay(10);
  Wire.write(AdcRead);
  Wire.requestFrom(Address, 3);
  while(Wire.available())
  {
    ByteHigh = Wire.read();
    ByteMiddle = Wire.read();
    ByteLow = Wire.read();
  }
  AdcPressure = ((long)ByteHigh << 16) + ((long)ByteMiddle << 8) + (long)ByteLow;
  }
  
void MS5803::readT() {

  Wire.beginTransmission(Address);
  Wire.write(D2_512);
  delay(10);
  Wire.write(AdcRead);
  Wire.requestFrom(Address, 3);
  while(Wire.available())
  {
    ByteHigh = Wire.read();
    ByteMiddle = Wire.read();
    ByteLow = Wire.read();
  }
  AdcTemperature = ((long)ByteHigh << 16) + ((long)ByteMiddle << 8) + (long)ByteLow;
  }
  
  void MS5803::calcT() {
   
  TempDifference = (float)(AdcTemperature - ((long)CalConstant[5] << 8));
  Temperature = (TempDifference * (float)CalConstant[6])/ pow(2, 23);
  Temperature = Temperature + 2000;  


  if (Temperature < 2000.0)  
  {
    T2 = 3 * pow(TempDifference, 2) / pow(2, 33);
    Off2 = 1.5 * pow((Temperature - 2000.0), 2);
    Sens2 = 0.625 * pow((Temperature - 2000.0), 2);
  }
  else
  {
    T2 = (TempDifference * TempDifference) * 7 / pow(2, 37);
    Off2 = 0.0625 * pow((Temperature - 2000.0), 2); 
    Sens2 = 0.0;
  }
  Temperature = Temperature / 100; 

  }
  
  void MS5803::calcP() {
	Offset = (float)CalConstant[2] * pow(2,16);
	Offset = Offset + ((float)CalConstant[4] * TempDifference / pow(2, 7));

	Sensitivity = (float)CalConstant[1] * pow(2, 15);
	Sensitivity = Sensitivity + ((float)CalConstant[3] * TempDifference / pow(2, 8));

	Offset = Offset - Off2;
	Sensitivity = Sensitivity - Sens2;

	Pressure = (float)AdcPressure * Sensitivity / pow(2, 21);
	Pressure = Pressure - Offset;
	Pressure = Pressure / pow(2, 15);
	Pressure = Pressure / 100;  // Set output to bars;
	
	
	}

How i can access Pressure and Temperature result from arduino sketch ? When i try to copmpile it says that Temperature was not declared.

Why have a class that returns no data?
The readT() function should return a value?
Did you write the library?

How i can access Pressure and Temperature result from arduino sketch ?

They are global in the library. Add

extern float Temperature;
extern float Pressure;

to your sketch to make them available in your sketch.

Though I agree with Mike. That library is crap. It misuses global variables all over the place.

Yes I made that crappy library . I dont know exactly how to write properly librariers where to declare variables used for calcultions and where to declare sensor HEX command for sensor. So i think the best way is to make a new library that is correctly made.

So i think the best way is to make a new library that is correctly made.

Yep. That means that any function with read in its name should return a value.