Converting A String To A Number

Question:

How do you convert a string to a number?

Code:

public class StringToNumber {
 
   public static void main(String[] args) {
 
      String str1 = "100";
      // int primitive
      int i1 = Integer.parseInt(str1);
      // Integer Object
      Integer i2 = Integer.valueOf(str1);
 
      String str2 = "3.14";
      // float primitive
      float f1 = Float.parseFloat(str2);;
      // Float Object
      Float f2 = Float.valueOf(str2);
 
      String str3 = "123456789";
      // double primitive
      double d1 = Double.parseDouble(str3);
      // Double Object
      Double d2 = Double.valueOf(str3);
 
   }
}