Running objarr_demo.js

// CPCS-324 Algorithms and Data Structures 2
// Language demo - Array of objects
// 2020, Dr. Muhammad Al-Hashimi

// note output string inside a paragraph <p></p>
document.write( "<p>Array of Objects:</p>" );

// ---------------------------------------------------------
// define object literal (or constant) inside { }
// vertex is array of 2 objects (formatted to clarify syntax)

var vertex = [
   {label: "a", adjacent: null},
   {label: "b", adjacent: null}

   ];

// a vertex object has 2 property fields (also called member
// variables): label, adjacent
// we can add other fields such as "visit" to mark visited 
// vertices, or "color" to classify vertices

// ---------------------------------------------------------
// reference a vertex using usual array notation, example: 
// vertex[0], vertex[1] etc.
document.write("<p>2nd vertex: ", vertex[1], "</p>");

// reference property field using usual "." notation,
// example: vertex[0].label
document.write("<p>Label of first vertex is: ", vertex[0].label, "</p>");

// note document.write() can't show user object details
// you write your own code to show vertex fields

document.write("<p>{ Label: ", vertex[1].label, ", Adjacent: ", vertex[1].adjacent, " }</p>");

// note array (assigned to vertex), a standard
// format called JSON: Javascript Object Notation
// more on this later (see json.org)