匹配两个json是否相同

function _diff(a,b){
  if(typeof a != typeof b || a.length != b.length)return false;
  if(typeof a == 'object'){
    for(var i in a){
      if(typeof b[i] == 'undefined')return false;
      if(!_diff(a[i],b[i]))return false;
    }
    return true;
  }else{
    return a === b;
  }
}

_diff({a:2,b:2,c:{c1:1,c2:2,c3:{c3:333}}},{a:2,b:2,c:{c1:1,c2:2,c3:{c3:333,c4:444}}})
//true
_diff({a:2,a1:[{a1:1}],b:2,c:{c1:1,c2:2,c3:{c3:333,c4:444,c6:[1,2]}}},{a:2,a1:[{a1:2}],b:2,c:{c1:1,c2:2,c3:{c3:333,c4:444,c6:[1,2]}}})
//false
_diff({a:2,a1:[{a1:2}],b:2,c:{c1:1,c2:2,c3:{c3:333,c4:444,c6:[1,2]}}},{a:2,a1:[{a2:2}],b:2,c:{c1:1,c2:2,c3:{c3:333,c4:444,c6:[1,2]}}})
//false