0

can anyone tell me actually what it is (var abc={} <==this one is object or?) if that is object what different between var abc=new Object() and var abc={}; Another question is scanner scan =new Scanner(); is same concenpt with var abc= new Object(): ??

Wang Liangwei
  • 59
  • 6
  • `this one is object or` empty object, yes - `what different between` nothing significant `is scanner scan =new Scanner()` yes - any early introduction to Javascript would cover all of this (except you don't `scanner scan = new Scanner()` you `var scan = new Scanner()` (or use `let` or `const` in place of `var`) - javascript has little concept of *static types* so you don't declare a variable as a particular type – Jaromanda X May 17 '18 at 02:53

2 Answers2

2

Objects can be defined by either of these two methods:

var abc = {};
var abc = new Object();

There is minimal difference between the two, however the first method is preferred by most.
If Scanner is of type Function then you instantiate it like so:

var scan = new Scanner();

The Scanner function might have been created like this:

function Scanner(total = 5){
   this.scans = total;
}

You could use this function like this:

var scan = new Scanner();

console.log(scan); // Output: Object
console.log(scan.scans); // Output: 5

scan = new Scanner(100);

console.log(scan.scans); // Output: 100

scan.scans = 50;

console.log(scan.scans); // Output: 50

var scan2 = { scans: 5 };

console.log(scan2); // Output: Object
console.log(scan2.scans); // Output: 5
Avikar
  • 151
  • 6
2

For an empty object, both var abc = {} and var abc = new Object() works but there are different approaches with different scenarios/requirements to choose the appropriate style.

You can read more at: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects Go to "Creating new objects"

For var scanner = new Scanner();

Scanner must be a function.

Deependra Rajput
  • 42
  • 5