Document ID: ./input/supremecourt_opinions/opinions/20pdf/18-956_d18f.pdf
Page Number: 9.0

Cite as:  593 U. S. ____ (2021) 

5 

Opinion of the Court 

i.e., which task it should carry out?  You do so by entering
into your own program a command that corresponds to the 
specific task and calls  it up.   Those commands, known as 
“method  calls,”  help  you  carry  out  the  task  by  choosing 
those programs written in implementing code that will do
the trick, i.e., that will instruct the computer so that your
program will find the higher of two numbers.  If a particular 
computer might perform, say, a million different tasks, dif-
ferent  method  calls  will  tell  the  computer  which  of  those
tasks to choose.  Those familiar with the Java language al-
ready know countless method calls that allow them to in-
voke countless tasks. 

And  how  does  the  method  call  (which  a  programmer 
types) actually locate and invoke the particular implement-
ing code that it needs to instruct the computer how to carry
out a particular task?   It does so through another type of
code, which the parties have labeled “declaring code.”  De-
claring code is part of the API.  For each task, the specific
command entered by the programmer matches up with spe-
cific declaring code inside the API.  That declaring code pro-
vides both the name for each task and the location of each 
task within the API’s overall organizational system (i.e., the 
placement  of  a  method  within  a  particular  class  and  the 
placement of a class within a particular package).  In this 
sense, the declaring code and the method call form a link,
allowing  the  programmer  to  draw  upon  the  thousands  of 
prewritten tasks, written in implementing code.  See id., at 
979–980.  Without that declaring code, the method calls en-
tered by the programmer would not call up the implement-
ing code.

The  declaring  code  therefore  performs  at  least  two  im-
portant functions in the Sun Java API.  The first, more ob-
vious,  function  is  that  the  declaring  code  enables  a  set  of 
shortcuts for programmers.  By connecting complex imple-
menting code with method calls, it allows a programmer to