javascript - Difference in calling method on object or passing object as function argument -

what difference in calling method on object or passing object function argument, , accordingly how pass argument in method call? putting placeholder argument didn't produced desired effect. have iterate trough property names(not values) , compare given argument (as property name) real property name in object?

here heavily commented piece of code, because i'm curious happening.

// create object constructor  function foo(prop1, prop2) {     this.prop1 = prop1;     this.prop2 = prop2;     // create object method printobjectpropertym      // , retreive property value     // * there m @ end of property distinguish      // method/function name      // how can add placeholder/argument in method ,     // call method on object provided argument (here prop1 or prop2)     this.printobjectpropertym = function() {         console.log(this.prop1);     }; }  // instantiate new object bar of foo type var bar = new foo("prop1val", "prop2val");  // create function print object property , take object argument var printobjectproperty = function(object) {     console.log(object.prop1); };  // call printobjectproperty bar object argument printobjectproperty(bar); // logs prop1var in console  // call bar method printobjectpropertym bar.printobjectpropertym(); // logs prop1val in console 

please kind , correct me if wrong in comments, code or pseudocode.

solution

you should use [] notation access object's property name.

create method inside constructor:

function foo(prop1val, prop2val) {    this.prop1 = prop1val;    this.prop2 = prop2val;    this.printproperty = function (name) {       if (this.hasownproperty(name)) {          console.log(this[name]);       }    } } 

now call it:

var bar = new foo("prop1val", "prop2val"); bar.printproperty("prop1"); 

links

1. property accessors - javascript | mdn
2. hasownproperty - javascript | mdn