Pnr (swe) and EAN checksum prototype

String.prototype.ean = function(){var n=0;var d=(this+'0').split('').reverse();for(var i in d){n+=(i%2)?d[i]*3:+d[i]}return this+(10-(n%10))%10}
 
 
String.prototype.pnr = function(){var n=[];var d=(this).split(''); for(var i in d){n[i]=((+i+1)%2)?d[i]*2:+d[i]} d=n.join('').split(''); n=0; for(var i in d){n+=+d[i]} n=(10-(n%10)); return this + String(n).substr(String(n).length-1) }
 
//Map/reduce prn check
String.prototype.pnr_check = function(){ return 10-(this.slice(-10,-1).split('').map(function(n,i){ return ((+i+1)%2)?n*2:+n }).join('').split('').reduce(function(a,b){ return +a + +b; }) % 10) === +this.substr(-1); }