what is difference between size and length in java code example

Example: length vs length() method in java

length() : In String class we have length() method which is used 
to return the number of characters in string.
Ex : String str = “Hello World”;
System.out.println(str.length());
Str.length() will return 11 characters including space. 
  
length : we have length instance variable in arrays which will 
return the number of values or objects in array.
For example :
String days[]={” Sun”,”Mon”,”wed”,”thu”,”fri”,”sat”};
Will return 6 since the number of values in days array is 6