javascript - Node.js API wrapper for altcoin exchange -

i'm trying make simple market maker bot , need use variables bid, ask , spread in other functions calculate kind of buy/sell orders create. how pass these variables along? how come i'm able subtract (ask - bid) , not add (bid + 0.001)

npm poloniex.js

    function getspread() {      poloniex.getticker(function(err, data){     if (err){         console.log('error', err);         return;     }      var ask = data.btc_ltc.lowestask;     var bid = data.btc_ltc.highestbid;     var spread = ((ask - bid) / ask);      console.log('ask:', ask,'bid:', bid,'spread:', spread);       }); } 

in order pass these variables separate function, may -

var calculateorder = function (bid, ask, spread) {     // use variables }  function getspread() {     poloniex.getticker(function(err, data) {         if (err){             console.log('error', err);             return;         }          var ask = data.btc_ltc.lowestask;         var bid = data.btc_ltc.highestbid;         var spread = ((ask - bid) / ask);          calculateorder(bid, ask, spread);      }); } 

you should convert lowestask , highestbid numbers before doing mathematical operations on them

var ask = number(data.btc_ltc.lowestask); var bid = number(data.btc_ltc.highestbid);