Dynamic Array

I want to build the var struc dynamically using iteration something like what I have out lined below but properly:

var struc{};
for (var i = 0 ; i < 100 ; i++){
  struc =  struc  + "'" + i + "'" + : + "'" + i + "'
}
 The result should be like:
var struc = {'1':'1',
              '2':'2',
              '3':'3',
              '4':'4',
              '5':'5',
              '6':'6',
              '7':'7'
};