Better way to initialize a field in a .. (object?)

How is a proper way to initialize a field in a (struct? object?) ?  Right now I'm doing that below, in bold    totals = _.reduce(findObjs({ pageid: page, type: 'graphic', isdrawing: false, layer: 'objects' }),function(m,o){ m.bar1+=parseFloat(o.get('bar1_value'),10) || 0; m.bar2+=parseFloat(o.get('bar2_value'),10) || 0; m.bar3+=parseFloat(o.get('bar3_value'),10) || 0; if(m.numberOfcities > 0 ){ // Isn't there a better way/place to initialize a variable?       // variable is supposed to be zero or greater than zero, so if greater do nothing }else{      m.numberOfcities = 0; }

found it, you put it at the end totals = _.reduce(findObjs({ pageid: page, type: 'graphic', isdrawing: false, layer: 'objects' }),function(m,o){ return m; },{ bar1: 0, bar2: 0, bar3: 0, numberOfcities: 0});