1. API PROGRAMMING

2. Application programming interface
In computer programming, an application programming interface (API) is a set
Of subroutine definitions, protocols, and tools for building software and
applications. A good API makes it easier to develop a program by providing all
the building blocks, which are then put together by the programmer. An API
may be for a web-based system, operating system, database system,
computer hardware, or software library. An API specification can take many
forms, but often includes specifications for routines, data structures, object
classes, variables, or remote calls. POSIX, Microsoft Windows API, the
C++ Standard Template Library, and Java APIs are examples of different forms
of APIs. Documentation for the API is usually provided to facilitate usage.
The status of APIs in intellectual property law is controversial.

3. Application programming interface

4. What is an API? - Fast Tech Skills

5. Introduction to API Design

6. Simple Drag and Drop Coding
<style type="text/css">#div1 {
width: 350px;
height: 70px;
padding: 10px;
border: 1px solid #aaaaaa; }
</style>
<script>
function allowDrop(ev) {
ev.preventDefault();
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);
function drop(ev) {
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
</script>
<p>Drag the W3Schools image into the rectangle:</p>
<div id="div1" ondragover="allowDrop(event)" ondrop="drop(event)"> </div>
<p><br />
<img draggable="true" height="69" id="drag1" ondragstart="drag(event)" src=" width="336" /></p>

7. I make a DandD Menu

11. <style type="text/css">#div1 {
width: 350px;
height: 70px;
padding: 10px;
border: 1px solid #aaaaaa; }

12. </style>
<script>
function allowDrop(ev) {
ev.preventDefault(); }
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);

13. function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data)); }

14. </script>
<p>Drag the W3Schools image into the rectangle:</p>
<div id="div1" ondragover="allowDrop(event)" ondrop="drop(event)"> </div>

15. <p><br />
<img draggable="true" height="69" id="drag1" ondragstart="drag(event)" src=" width="336" /></p>

16. Drag the picture to above BOX.