Difference between object and object.prototype in Javascript -

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• how new operator work in javascript? 2 answers

ok here's bit of code working atm.

my problem don't difference between object , object prototype. until thought, if make new object, e.g. new memory, inherits properties declared in memory. in code, however, need add options memory.prototype.

so core question is: difference between properties of object , properties of object.prototype?

edit: specify: in memory function log this.options. doesn't work, unless include memory.prototype.options = {...}. if new memory inherits properties memory , defined e.g this.options.availablecards above, why need add options prototype?

var creatememory = function (){         new memory( {wrapperid: 'memory-game'} );       };        var memory = function (options) {         //check required options         if ((options.wrapperid === undefined)){           console.error('error: not required options given. wrapperid required!');           return false;         }          //hardcoded values         this.options.availablecards = 22;         this.options.cols = 4;         this.options.rows = 4;         this.options.fliptime = this.options.fliptime || 1; //set default         this.options = extend({}, this.options);         extend(this.options, options);         //this._init();         console.log(this.options);        };         // why required?        memory.prototype.options = {          ongameend: function(){            return false;          }        };         creatememory(); 

you forgot return new object in creatememory.

a few other fixes , had invent extend function, since didn't include yours.

//extend function  function extend(a, b) {      (var in b) {        if (b.hasownproperty(i)) {          a[i] = b[i];        }      }      return a;    }    //memory class    function memory(options) {    //check required options    if ((options.wrapperid === undefined)) {      console.error('error: not requried options given. wrapperid requried!');      return false;    } // hardcoded values      this.options.availablecards = 22;    this.options.cols = 4;    this.options.rows = 4;    this.options.fliptime = this.options.fliptime || 1;    this.options = extend({}, this.options);    extend(this.options, options);    //this._init();  };  memory.prototype.options = {    ongameend: function() {      alert("inherited")    }  };  //instantiater  function creatememory() {    return new memory({      wrapperid: 'memory-game'    });  };    //instantiate  var m = new creatememory();  //call inherited  console.log(m);  m.options.ongameend();

properties of object specific instance of object, while properties of prototype shared among instances of object.

if, instance, have id number each instance, id property needs on object since unique instance.

conversely, if had method exact same of instances, can save on memory putting in prototype , inherit it.