dinámicamente seleccione un atributo de objeto javascript

Question

[¿Cómo] puedo lograr lo siguiente?

var object = new Object(); 
object.field1 = "test1"; 
object.fiedl2 = "test2"; 

function showSpecificField(fieldName){ 
    //get the field Name passed in to function from object 
    //something like: return object.fieldName ??? 
} 

alert(showSpecificField("field2"));// should alert the text "test2" 

alert(showSpecificField("field1"));// should alert the text "test1" 

Answer 1

Uso square bracket notation

var baz = 'bar'; 
foo['bar'] === foo.bar === foo[baz]