数组项ReferenceError问题：Google Apps Script列标题切换脚本报错

Let's break down what's going wrong and fix your script step by step:

The Root Cause of the Error #

The ReferenceError: "Today" is not defined happens because you're using Today as if it's a variable, but it's actually a text string in your cells. In JavaScript (which Google Apps Script uses), unquoted words are treated as variables—since you never declared a variable named Today, the script throws an error.

Other Issues in the Original Code #

Besides the variable mistake, there are a couple more problems:

• You can't call setValues() on the array returned by getValues()—that method belongs to a Range object, not an array.
• Directly comparing arrays with == doesn't work as expected in JavaScript; we need to check the actual values inside the array.
• Some syntax errors (missing quotes around empty spaces, inconsistent variable names like newRoutine vs newToday).

Corrected Script #

Here's the fixed version that will toggle the "Today" header between the 3 columns:

function Progressions() {
  var workoutSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Workouts");
  // Get the range containing the 3 headers (row 2, columns 1-3)
  var headerRange = workoutSheet.getRange(2, 1, 1, 3);
  // Get the values as a 2D array: [[col1Val, col2Val, col3Val]]
  var currentHeaders = headerRange.getValues()[0]; // Extract the first (and only) row as a 1D array
  
  var newHeaders;
  
  // Check where "Today" is currently located
  if (currentHeaders[0] === "Today") {
    // Move "Today" to the second column
    newHeaders = ["", "Today", ""];
  } else if (currentHeaders[1] === "Today") {
    // Move "Today" to the third column
    newHeaders = ["", "", "Today"];
  } else if (currentHeaders[2] === "Today") {
    // Move "Today" back to the first column
    newHeaders = ["Today", "", ""];
  }
  
  // Update the range with the new headers
  if (newHeaders) {
    headerRange.setValues([newHeaders]); // Wrap the 1D array in another array for setValues()
  }
}

Key Fixes & Improvements #

• Quoted "Today": Now we use "Today" (a string) instead of Today (an undefined variable).
• Range vs Array: We keep track of the original headerRange so we can call setValues() on it later (instead of trying to call it on the array of values).
• Simplified Value Checks: We extract the 1D array of header values and check the index of "Today" directly, making the logic easier to read.
• Proper Array Formatting: setValues() expects a 2D array, so we wrap our 1D newHeaders array in another array when passing it to the method.

How to Test #

1. Replace your existing code with this version in the Apps Script editor.
2. Make sure your "Workouts" sheet has row 2, columns A-C set up with one cell containing "Today" and the others empty (adjust the empty string checks if you use a different placeholder).
3. Run the Progressions function—each run should move "Today" to the next column, looping back to the first after the third.

内容的提问来源于stack exchange，提问作者Dan Howard