Calculate the last digit verification code of the EAN-13 standard bar code using Javascript

Today, I saw my colleagues in the Group talking about the last verification code of the EAN-13 standard bar code, so I wrote this algorithm with js. Today's Monday is the beginning of a week. I wish you a good mood every day!

/*

The calculation steps of the last digit verification code of the EAN-13 standard Bar Code are as follows:

A. The sum of all the even digit codes starting from code position 2.

B. Multiply the sum of step a by 3.

C. sum the numeric codes of all odd digits starting from code position 3.

D. Add the result of step B and Step c.

E. Use a number greater than or equal to step d and a minimum integer multiple of 10 minus step d. The difference is the value of the obtained verification code. Explanation: EAN-13 standard bar code positions from right to left serial 13 12 11 10 9 8 7 6 5 4 3 2 1

Author: wangfan

Created on:

*/Function isBarCode (s ){

Var reg = new RegExp (/^ [0-9] {12} $ /);

If (reg.exe c (s. substring (0, 12) return true;

Else return false;

}

Function CheckBarCode (s)

{

If (! IsBarCode (s ))

{

Return "An error occurred while verifying the first 12 digits of the barcode! ";

}

Var a = 0;

Var B = 0;

Var c = 0;

Var d = 0;

Var e = 0;

For (var I = 1; I <= 12; I ++)

{

Var SC = parseInt (s [I-1]);

If (I <= 12 & I % 2 = 0)

{

A + = SC;

}

Else if (I <= 11 & I % 2 = 1)

{

B + = SC;

}

}

C = a * 3;

D = B + c;

If (d % 10 = 0)

E = d-d;

Else

E = d + (10-d % 10)-d;

Return e;

}

Alert ("Check Code:" + CheckBarCode ("693721090010X "));