Prototype : It provides ingeritance, objects can have a prototype object, which acts as a template object that it inherits methods and properties from.
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<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
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<script>
/*
var arr=new Array('a','b','c','d','e');
function getRandomFromArray(arr){
var index=Math.floor(arr.length*Math.random());
//get random integer as long as length of arr
//Math.floor returns the largest or equal integer that is less than given value
return arr[index];
}
console.log(getRandomFromArray(arr));
*/
Array.prototype.random=function(){ //random method added to Array object
//random is obviously belong to Array
var index=Math.floor(this.length*Math.random());//this indicates Arary
return this[index];
}
var arr=new Array('a','b','c','d','e');
console.log(arr.random());
</script>
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