将JavaScript字符串转换为多维数组

function convertStringToMultiArray(str) {
  // Step 1: Split the string into an array of substrings
  var substrings = str.split(";");

  // Step 2: Split each substring into a 2D array
  var multiArray = substrings.map(function(substring) {
    return substring.split(",");
  });

  // Step 3: Convert each element to a number (if needed)
  multiArray = multiArray.map(function(subarray) {
    return subarray.map(function(element) {
      return parseInt(element);
    });
  });

  return multiArray;
}

// Example usage
var str = "1,2,3;4,5,6;7,8,9";
var multiArray = convertStringToMultiArray(str);
console.log(multiArray);

[
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
]