How could I convert a byte to an int?

I understand how I could using normal Java, but I don't know how or nonetheless if I can even accomplish this by using the Arduino language. Could someone please help me out with this? Any help would be greatly appreciated!

byte b = 5;
int x = b;

that's about it.

the Arduino language

sp. "C++"

I have the bytes being sent over to me through my COM3 port, if that makes a difference.

I tried your stated method, and it did not work.

Can you post your failing sketch?

and it did not work

Which means what, exactly?
Have you got a sign-extension problem?

#include <LiquidCrystal.h>

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

void setup(){
  lcd.begin(16, 2);

  lcd.clear();
  
  lcd.print("Today's Forecast");
  
  Serial.begin(9600);
}


void loop()
{
  byte byteRead;
  String weather;
  int cur = 1;
  int x;
  
  lcd.setCursor(0,1);

  if (Serial.available()) {
    if (cur = 1){
      byteRead = Serial.read();
      x = byteRead;
      weather = "Hi " + x;
      cur ++;
    } else if (cur = 2){
      byteRead = Serial.read();
      x = byteRead;
      weather = weather + "Lo " + x;
      cur ++;
    } else if (cur = 3){
      byteRead = Serial.read();
      x = byteRead;
      weather = "P " + x;
    }  
  }
  lcd.print(weather);
}

The LCD outputs:

if (cur = 1){

?

try this, code not tested

#include <LiquidCrystal.h>

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

void setup()
{
  lcd.begin(16, 2);
  lcd.clear();
  lcd.print("Today's Forecast");

  Serial.begin(9600);
}

void loop()
{
  int cur = 1;

  lcd.setCursor(0,1);

  if (Serial.available()) 
  {
    byte  byteRead = Serial.read();
    int x = byteRead;

    if (cur == 1)
    {
      lcd.print("Hi:");
      lcd.print(x, DEC);
      cur ++;
    } 
    else if (cur == 2)
    {
      lcd.print("Lo:");
      lcd.print(x, DEC);
      cur ++;
    } 
    else if (cur == 3)
    {
      lcd.print("P:");
      lcd.print(x, DEC);
    }  
  }
}

The code prints "Hi:" correctly, but it breaks the loop there.

The output is: "Today's Forecast" and "Hi: 48"

Your code is reading one byte. That one byte is ONE character of a string that represents the temperature. It is NOT the complete temperature.

You need to read and store the characters until the end of the temperature portion arrives (you get to figure out what the "end of temperature portion" means), and then convert the stored characters (not bytes) to an int.

Alternatively, you can use Serial.parseInt() to do that.