JavaScript Array Properties

Table of Contents

constructor

In JavaScript, the constructor property returns the constructor function for an object. For JavaScript arrays the constructor property returns function Array() { [native code] }


var fruits = ['Banana', 'Orange' ,'Apple'];
fruits.constructor ;

//Returns
// function Array() { [native code] }

length

The length property sets or returns the number of elements in an array.


var fruits = ['Banana', 'Orange' ,'Apple'];
fruits.length ;

//Returns 3

var vegetables = [];
vegetables.length = 3;
// function Array length to 3

prototype

The prototype constructor allows you to add new properties and methods to the Array() object.


//Make a new array method

Array.prototype.myUcase = function(){
 for (i=0; i < this.length;i++){
  this[i] = this[i].toUpperCase();
 }
}
// Make an array, then call the myUcase method:
var fruits = ['Banana', 'Orange' ,'Apple'];
fruits.myUcase();

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