title: Double cannot be converted to boolean
body: <p>Having trouble with the if statement. It gives me the error "Double cannot be converted to boolean." 
  Some help would be appriciated</p>
  
  <pre><code>import java.util.Scanner;
  
  public class Temperatures {
  
      public static void main(String[] args) {
  
          Scanner reader = new Scanner(System.in);
          // Write your code here. 
          while(true){
              System.out.println("Enter a temperature: ");
              double value = reader.nextDouble();
  
  
              if ( value =&gt; 40 &amp;&amp; value &lt;= -30){
                  System.out.println("Too high or low temperature, try again");
              }else{
                  Graph.addNumber(value);
              }
              if (value == 00){
                  break;
              }
          }
  
      }
  }
  </code></pre>