Sense Temperature And Humidity Around You On Just A Click

#include <dht.h>

dht DHT;
#define DHT11_PIN 12 
char junk;
String inputString="";

void setup()                    // run once, when the sketch starts
{
 Serial.begin(9600);            // set the baud rate to 9600, same should be of your Serial Monitor
 pinMode(13, OUTPUT);
}

void loop()
{
  if(Serial.available()){
  while(Serial.available())
    {
      char inChar = (char)Serial.read(); //read the input
      inputString += inChar;        //make a string of the characters coming on serial
    }
    Serial.println(inputString);
    while (Serial.available() > 0)  
    { junk = Serial.read() ; }      // clear the serial buffer
    if(inputString == "a"){         //in case of 'a' turn the LED on
      digitalWrite(13, HIGH); 
      


int chk=DHT.read11(DHT11_PIN);
Serial.print("TEMPERATURE = ");
Serial.println(DHT.temperature);  
Serial.print("HUMIDITY = ");
Serial.println(DHT.humidity);
delay(750);
      
    }else if(inputString == "b"){   //incase of 'b' turn the LED off
      digitalWrite(13, LOW);
    }
    inputString = "";
  }
}