javascript - Clean way to test many conditions of different values? -

so , want test many conditions, different values... right bunch of if,else statements...

but looks ugly im sure there must better way...

any ideas ?

im thinking maybe loops or putting vars in array, cant figure out how..

thx!

var dataobject = {}  if (newstate.playerid){   dataobject["filter[player_id]"] = newstate.playerid }else{   dataobject["filter[player_id]"] = this.state.playerid }  if (newstate.pagelimit){   dataobject ["page[limit]"] = newstate.pagelimit }else{   dataobject["page[limit]"] = this.state.pagelimit }  if (newstate.timefrom){   dataobject["time[from]"] = newstate.timefrom }else{   dataobject["time[from]"] = this.state.timefrom }  if (newstate.timeto){   dataobject["time[to]"] = newstate.timeto }else{   dataobject["time[to]"] = this.state.timeto }  if (newstate.gameid){   dataobject["filter[game_id]"] = newstate.gameid }else{   dataobject["filter[game_id]"] = this.state.gameid }  if (newstate.customerid){   dataobject["filter[customer_id]"] = newstate.customerid }else{   dataobject["filter[customer_id]"] = this.state.customerid }  if (newstate.currency){   dataobject["filter[currency]"] = newstate.currency }else{   dataobject["filter[currency]"] = this.state.currency }  if (newstate.variant){   dataobject["filter[locale]"] = newstate.locale }else{   dataobject["filter[locale]"] = this.state.locale }  if (newstate.variant){   dataobject["filter[demo]"] = newstate.demo }else{   dataobject["filter[demo]"] = this.state.demo } 

reducing condition

first, can use javascript's || operator , change:

if (newstate.playerid){   dataobject["filter[player_id]"] = newstate.playerid }else{   dataobject["filter[player_id]"] = this.state.playerid } 

to reduced:

dataobject["filter[player_id]"] = newstate.playerid || this.state.playerid; 

dry code

you can use array of properties:

var propertylist = ["playerid", "pagelimit", "timefrom" /* etc. */] 

because object properties can referenced using square brackets can loop through them this:

propertylist.foreach(function(property){     dataobject[property] = newstate[property] || this.state[property] }); 

disclaimer: solution not taking account embedded objects (like "filter") , slight variations in naming schemes (like "player_id" vs "playerid").

three solutions occur me:

1. use consistent naming conventions
   in other words in dataobject build have same naming pattern state object.

2. use helper function
   convert names in loop using kind of consistent pattern changes playerid player_id when kinds of changes need done. (this still not work if plan use "filter", "time" or "page".

3. use objects/arrays (as in @ssube's solution)
   use array or object translate property names between objects. won't give example - @ssube has done already.