javascript - Default arguments in functions which defined in object -

here code:

mymodel =  {   get: function(key, model) {     if(typeof(model) === 'undefined') {   //       model = model.get();                //     }                                     //     return model.data[key];   },   getall: function(model) {     if(typeof(model) === 'undefined') {       model = model.get();     }     return model.data;   },   save: function(data, model) {     if(typeof(model) === 'undefined') {       model = model.get();     }     model.save(data);   },   //... } 

the a part repeats.

is there way more beautiful?

something get: function(key, model = model.get());

from mdn, not work in many browsers.

function setbackgroundcolor(element, color = 'rosybrown') {   element.style.backgroundcolor = color;  }  setbackgroundcolor(somediv);            // color set 'rosybrown' setbackgroundcolor(somediv, undefined); // color set 'rosybrown' setbackgroundcolor(somediv, 'blue');    // color set 'blue' 

you can make function in object, keeping code dry

getmodel: function(model){    return model || model.get(); } 

now use following in blocks need model.

var test_model = this.getmodel(model);