This tutorial will help a user to learn how to create a property with specified attribute values or modify the attributes of a property that already exists in JavaScript

1. Creating a property:

// using Object.defineProperty() for creating a new property

var abc = {};

// define a property and assign its value and attributes


Object.defineProperty(abc, "xyz",{ value : Hello World, writable: true, enumerable: false, configurable: true});

document.write(abc["xyz"]);     // output: Hello World

2. Modifying a property:

<script>

// using Object.defineProperty() for creating a new property

var abc = {lm: Hello World};

document.write(abc["lm"]);      // output: Hello World

// define a property and assign its value and attributes

Object.defineProperty(abc, "lm",{ value : 'Hello Everybody', writable: true, enumerable: false, configurable: true});

document.write(abc["lm"]);            // output: Hello Everybody
</script>

3- Making a property read-only

//To make a JavaScript execute in a strict mode we write use strict on top of the script file.

<script>
 "use strict"

var abc = {"xyz":562};

Object.defineProperty(abc, "xyz", { writable: false} );

abc["xyz"] = 420;                   

// if we use strict mode, then it's we get the following error

// TypeError: "xyz" is read-only 

// if we use non strict mode we get the following output

document.write(abc["xyz"]);         // output: 562        
</script>

4- creating/modifying multiple properties of an object

<script>
var abc = {};

// here we will add 2 properties, with their attributes in the object abc

Object.defineProperties(
    abc,
    {
        prop1:{ value : 'Hello World', writable: true, enumerable: true, configurable: true},
        prop2:{ value : 'Thank you', writable: true, enumerable: true, configurable: true}
    }
);

console.log(abc);               // Object{ prop1: Hello World, prop2: Thank you }

</script>