BarreCode EAN encoding

I try to generate the encoding of the EAN13 barcode in order to obtain for the code 6181100327649 the following line 6BSLLAA*dchgej+
This to be able to use the EAN font and generate in my creative visuals.
Here is my code but it does not work :

function EAN(chaine) {
var i           = 0;
var first       = 0;
var checksum    = 0;
var CodeBarre   = "";
var tableA      = 0;

        if(chaine.match("/^\d{12}$/")){
                for (i = 1; i < 12; i += 2)
                {
                    chaine.substr(i, 1);
                    checksum += parseInt(chaine.substr(i, 1));
                }
                checksum *= 3;
                for (i = 0; i < 12; i += 2)
                {
                    checksum += parseInt(chaine.substr(i, 1));
                }

                chaine += (10 - checksum % 10) % 10;
                CodeBarre = chaine.substr(0, 1) + (chaine.fromCharCode(65 + parseInt(chaine.substr(1, 1)) ));
                first = parseInt(chaine.substr(0, 1));
                for (i = 2; i <= 6; i++)
                {
                    tableA = false;
                    switch (i)
                    {
                        case 2: if (first >= 0 && first <= 3) tableA = true; break;
                        case 3: if (first == 0 || first == 4 || first == 7 || first == 8) tableA = true; break;
                        case 4: if (first == 0 || first == 1 || first == 4 || first == 5 || first == 9) tableA = true; break;
                        case 5: if (first == 0 || first == 2 || first == 5 || first == 6 || first == 7) tableA = true; break;
                        case 6: if (first == 0 || first == 3 || first == 6 || first == 8 || first == 9) tableA = true; break;
                    }

                    if (tableA)
                        CodeBarre += (chaine.fromCharCode(65 + parseInt(chaine.substr(i, 1)) ));
                    else
                        CodeBarre += (chaine.fromCharCode(75 + parseInt(chaine.substr(i, 1)) ));
                }
                CodeBarre += "*";

                for (i = 7; i <= 12; i++)
                {
                    CodeBarre += (chaine.fromCharCode(97 + parseInt(chaine.substr(i, 1)) ));
                }
                CodeBarre += "+";
            }
            return CodeBarre;
        }
document.getElementById("demo").innerHTML = EAN("618110032764"); 

>Solution :

There was mutliple issues here, but here is a working example for you

function getCharCode(chaine, index, position) {
  return String.fromCharCode(position + parseInt(chaine.substr(index, 1)));
}

function EAN(chaine) {
  var i = 0;
  var first = 0;
  var checksum = 0;
  var CodeBarre = "";
  var tableA = 0;

  if (chaine.match(/^\d{12}$/)) {
    for (i = 1; i < 12; i += 2) {
      chaine.substr(i, 1);
      checksum += parseInt(chaine.substr(i, 1));
    }
    checksum *= 3;
    for (i = 0; i < 12; i += 2) {
      checksum += parseInt(chaine.substr(i, 1));
    }

    chaine += (10 - checksum % 10) % 10;
    CodeBarre = chaine.substr(0, 1) + getCharCode(chaine, 1, 65);
    first = parseInt(chaine.substr(0, 1));
    for (i = 2; i <= 6; i++) {
      tableA = false;
      switch (i) {
        case 2:
          if (first >= 0 && first <= 3) tableA = true;
          break;
        case 3:
          if (first == 0 || first == 4 || first == 7 || first == 8) tableA = true;
          break;
        case 4:
          if (first == 0 || first == 1 || first == 4 || first == 5 || first == 9) tableA = true;
          break;
        case 5:
          if (first == 0 || first == 2 || first == 5 || first == 6 || first == 7) tableA = true;
          break;
        case 6:
          if (first == 0 || first == 3 || first == 6 || first == 8 || first == 9) tableA = true;
          break;
      }

      if (tableA)
        CodeBarre += getCharCode(chaine, i, 65); 
      else
        CodeBarre += getCharCode(chaine, i, 75); 
    }
    CodeBarre += "*";

    for (i = 7; i <= 12; i++) {
      CodeBarre += getCharCode(chaine, i, 97); 
    }
    CodeBarre += "+";
  }
  return CodeBarre;
}

document.getElementById("demo").innerHTML = EAN("618110032764");

Among those issues :

• Regex shouldn’t be a string so no "" surrounding the expression
• fromCharCode is a static method, should be used with String.fromCharCode
• You should access characters from the string with the index on the loop

Here is the working demo: https://jsfiddle.net/t6r15qbd/1/