CRC-16 Hash Computation for Case Labels

CRC16-Javascript.js

	console.log("hello CRC16");

	function CreateCrc16(){
			var polynomial,value,temp;
			var table=new Array(256);
			
				polynomial=40961;
			for(i=0;i<table.length;++i){
				value=0;temp=i;
			for(j=0;j<8;++j){if(0!=((value^temp)&1)){
				value=(value>>1)^polynomial
			}else{
				value>>=1
			}
				temp>>=1
			}
				table[i]=value
			}return table
		}
		
		var crc,table,testString,index;
		var GTIN = "10850510002011";
		var Lot = "46587443HG234"
		var date = ""
		testString = "1088100603702601227131123456120112";
		
		console.log("Plain Text = " +testString);
		
		/*if(testString != ""){
			testString=GTIN+Lot+date;
		}*/
		
		crc=0;
		table=CreateCrc16();
		
		for(i=0;i<testString.length;++i){
			index=(crc^testString.charCodeAt(i))%256;
			crc=(crc>>8)^table[index]
		}
		
		console.log("crc = " +crc);
		
		var vc=(crc%10000)+"";
		var length=vc.length;
		for(i=vc.length;i<4;i++)
		{
			vc="0"+vc
		}

		console.log("Small Digits" + vc.substr(0,2));
		console.log("Large Digits" + vc.substr(2,2));