attempt1

gistfile1.js

function match_brackets(str){
 
 var stack = [],
   lookup = {
     //key : value pairs
     '(' : ')',
     '{' : '}',
     '[' : ']',
   },
   _keys = Object.keys(lookup),
   //right = lookup.values
   _values = Object.keys(lookup).map(function (key) {
       return lookup[key];
   });
   
   str.split("").forEach(function(char){
       
     if (_keys.indexOf(char) > -1){
         stack.push(char)
     }
     else if( _values.indexOf(char) > -1){
         
         if (stack.length == 0  || (char != lookup[stack[stack.length-1]] )) {
             return false
         }else{
             lookup[stack.pop()]
             
         }
     }
       
   })
   
   return (stack.length == 0)
}

//tests

console.log(match_brackets("{}"))   //true
console.log(match_brackets("{]"))   //false
console.log(match_brackets("{{}}")) //true