js-xlsx Uncaught TypeError: console.log is not a function

I am using xlsx for reading Excel file. It kinda works... At least first row. I don't know what's the problem so here I am.

this is my code:

  /* set up XMLHttpRequest */
  var url = "http://localhost/test.xlsx";
  var oReq = new XMLHttpRequest();
  oReq.open("GET", url, true);
  oReq.responseType = "arraybuffer";

  oReq.onload = function(e) {
    var arraybuffer = oReq.response;

    /* convert data to binary string */
    var data = new Uint8Array(arraybuffer);
    var arr = new Array();
    for(var i = 0; i != data.length; ++i) arr[i] = String.fromCharCode(data[i]);
      var bstr = arr.join("");

    /* Call XLSX */
    var workbook = XLSX.read(bstr, {type:"binary"});

    /* DO SOMETHING WITH workbook HERE */
    var alphabet = "ABC".split("");
    var first_sheet_name = workbook.SheetNames[0];

    /* Get worksheet */
    var worksheet = workbook.Sheets[first_sheet_name];
    var address_of_cell, desired_cell, desired_value;
    var descript;

    for (i=1;i<30;i++) {
      for (j=0;j<alphabet.length;j++) {
        if (alphabet[j] == "A") {
          console.log("This will be title: "+getValue(alphabet[j], i));
        } else if (alphabet[j] == "B") {
          descript = getValue(alphabet[j], i);
          console.log(""+descript);
        } else if (alphabet[j] == "C") {
          console.log="This will be description: " + descript+" - "+getValue(alphabet[j], i);
        }
      }
    }

    function getValue (column, row) {
      address_of_cell = column+''+row;
      console.log(address_of_cell);
      /* Find desired cell */
      desired_cell = worksheet[address_of_cell];
      /* Get the value */
      desired_value = desired_cell.v;
      return(desired_value);
    }
  };
  oReq.send();

Now the result I get in console is:

A1
This will be title: VI/46/1998
B1
30-12-1998
C1
Uncaught TypeError: console.log is not a function Bookmarklet.js:43

As You can see in C1 I get that console.log is not a fucntion, but why? Where's my mistake? What am I doing wrong?

Sincerely, Thomas

Solution

console.log is provided by the environment in which your code runs. Or not. It depends on the environment. Modern browsers provide it (at least if you have devtools open; some versions of IE don't provide it if you don't). NodeJS provides it.

Two possibilities:

Your environment doesn't provide it.
It does, but then you run this line of code:
```
console.log="This will be description: " + descript+" - "+getValue(alphabet[j], i);
```
which overwrites it with a string. Strings aren't functions, so the attempt to call it on any of your lines that use it correctly (like console.log(address_of_cell);) will now start failing.

That line should be like the others, a function call:
```
console.log("This will be description: " + descript+" - "+getValue(alphabet[j], i));
```