class - Same variablename and propertyname in a constructor in JavaScript -

consider following definition of class in javascript:

// car constructor function car(color) {     var haswheels = true;     this.color = color;     this.haswheels = haswheels; } var redcar = new car('red'); console.log(redcar.haswheels); 

it seems work because gives no errors in firefox , writes true console. however, code correct or javascript forgiving? netbeans complains in car constructor variable haswheels unused. not give hint haswheels when type redcar.. works property color. have rename variable haswheels e.g. _haswheels? (i know in simple example set property hasweels directly true, not point of question.) new code like:

// car constructor function car(color) {     var _haswheels = true;     this.color = color;     this.haswheels = _haswheels; } var redcar = new car('red'); console.log(redcar.haswheels); 

this seems work fine netbeans. however, rather gives properties , variables same name, since @ end assigned. this['haswheels'] = haswheels in last line of constructor seems not work.

for worth works fine in netbeans:

function car(color) {     var haswheels = true;     return {         color: color,         haswheels: haswheels     }; } var redcar = new car('red'); console.log(redcar.haswheels); 

yes, can have same name. function argument in same namespace function's local variables, properties of object different.

you can think of arguments , local variables items on local scope object (or scope chain) whereas properties of current object properties of object pointed this. 2 namespaces different. 1 reached no qualifier in color. other reached referencing object in this.color. so, this.color = color works fine - assigning variable's value 1 namespace property in object's namespace - 2 separate variables.

in example doesn't work:

// car constructor function car(color) {     var haswheels = true;     this.color = color;     this.haswheels = haswheels; } 

there should no issue there either , seems work fine here: http://jsfiddle.net/jfriend00/7psg9/