## E0108: 'in' disallowed in C-style for loop initializer

C-style `for` loops can have a expression the first `;`-separated part. It is an error for the expression to use the `in` operator without parentheses:

    for (let i = 'startAtOne' in opts ? 1 : 0;
         i < opts.count;
         ++i) {
      if (!processItem(data[i])) {
        break;
      }
    }

To fix this error, surround the `in` expression with parentheses:

    for (let i = ('startAtOne' in opts) ? 1 : 0;
         i < opts.count;
         ++i) {
      if (!processItem(data[i])) {
        break;
      }
    }

Documentation for other errors