javascript - How to operate on object based on string -

js noob here. if have string, how can call attribute object has same name string?

var carrot = {     'vitamina': 150,     'vitaminc': 100 };  var cucumber = {     'vitamina': 10,     'vitaminc': 12  };  var vegetable = 'cucumber' alert(vegetable.vitaminc) // doesn't work  

note: simplified version of problem i'm working on, can't alert(cucumber.vitaminc) -- have operate on object based on string

you can have like:

window[vegetable].vitaminc 

but highly suggest containing these guys in object not global object window:

var vegetables = {   cucumber : {     vitamina: 10,     vitaminc: 12   },   carrot : {     vitamina: 150,     vitaminc: 100   } };  var vegetable = 'cucumber'; alert(vegetables[vegetable].vitaminc);