Java convert String to double example

What is the difference between Double and double in Java?

Double is a class while double is a primitive. In other words, Double has a bunch of methods while all you can do with double is use it in arithmetical expressions.

Constructor Summary

• Double(double value)
• Constructs a newly allocated Double object that represents the primitive double argument.
• Double(String s)
• Constructs a newly allocated Double object that represents the floating-point value of type double represented by the string.

Method Summary

• static Double valueOf(double d)
• Returns a Double instance representing the specified double value.
• static Double valueOf(String s)
• Returns a Double object holding the double value represented by the argument string s.

Click here for java.lang.Double API docs

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package com.as400samplecode;   public class ConvertStringToDouble {       public static void main(String[] args) {           String myString = "400.99";         double mydouble = Double.parseDouble(myString);         System.out.println(mydouble);           Double myDouble = new Double(myString);         System.out.println(myDouble);           myDouble = Double.valueOf(myString);         System.out.println(myDouble);       }   }