I really need help fixing my errors

  1  import java.util.Scanner;
  2  
  3  public class MyCalculator {
  4      public static void main(String[] args) {
  5          Scanner scanner = new Scanner(System.in);
  6          // userInput
  7  
  8          // i searched online how to restart a program with y/n
  9          while (true) {
 10              // this is to get it to loop continuously if the user says yes
 11  
 12              while (true) {
 13                  System.out.println("Enter the calculator mode: Standard or Scientific? ");
 14                  String mode = scanner.nextLine();
 15  
 16                  if (mode.equalsIgnoreCase("Scientific")) {
 17                      System.out.println("Enter '+' for addition, '-' for subtraction, '*' for multiplication, '/' for division");
 18                      // equalsIgnoreCase because often people will put words in upper or lower case unless specified so it's important to account for that
 19                      System.out.print(", 'sin' for sin x, 'cos' for cos x, 'tan' for tan x: ");
 20                  }
 21  
 22                  String operation = scanner.nextLine();
 23  
 24                  if (operation.equals("+") || operation.equals("-") || operation.equals("*") || operation.equals("/")) {
 25                      System.out.print("How many numbers do you want to " + operation + "? ");
 26                      // how many numbers do you want to +, -, *, /
 27                      int count = scanner.nextInt();
 28                      scanner.nextLine(); // consume the newline character left in the buffer
 29                      double result = 0.0;
 30                      // operation.equals just sees if it's equal to what I put and then executes the code, I put a bunch of
 31                      // or statements because it's different operations
 32  
 33                      System.out.print("Enter " + count + " numbers: ");
 34                      for (int i = 0; i < count; i++) {
 35                          double number = scanner.nextDouble();
 36                          scanner.nextLine(); // consume the newline character left in the buffer
 37                          // check this part, I'm not sure if I messed up by using an int and double
 38                          switch (operation) {
 39                              // switch cases are really useful when you have different options, I learnt this in programming methods and we did an example where we did a switch case with numbers and months
 40                              // we learnt this in class weeks ago where you can use a switch case
 41                              // we did an example with numbers and months
 42                              case "+":
 43                                  result += number;
 44                                  break;
 45                              // we also learnt that break; terminates loops and I typically
 46                              // make my loops infinite but in this case we don't want that
 47                              case "-":
 48                                  result -= number;
 49                                  break;
 50                              case "*":
 51                                  result *= number;
 52                                  break;
 53                              case "/":
 54                                  result /= number;
 55                                  break;
 56                          }
 57                      }
 58                      System.out.println("Result: " + result);
 59                  } else if (mode.equalsIgnoreCase("Scientific") && (operation.equalsIgnoreCase("sin") ||
 60                          // .equals ignore case because some people might put scientific or Scientific and I don't want the program to crash because of something so small
 61                          // && is an operator and if the userInput meets the condition then the code will execute
 62                          operation.equalsIgnoreCase("cos") || operation.equalsIgnoreCase("tan"))) {
 63                      System.out.print("Enter a number in radians to find the " + operation + ": ");
 64                      double number = scanner.nextDouble();
 65                      scanner.nextLine(); // consume the newline character left in the buffer
 66                      // radians should be double not int because it is decimals
 67                      double result;
 68  
 69                      switch (operation) {
 70                          // another switch case to help execute different options
 71                          case "sin":
 72                              result = Math.sin(number);
 73                              // returns the sine of the number, we learnt in class how to use math.random and math.sqrt and others
 74                              break;
 75                          case "cos":
 76                              result = Math.cos(number);
 77                              break;
 78                          case "tan":
 79                              result = Math.tan(number);
 80                              break;
 81                          default:
 82                              result = 0.0;
 83                              break;
 84                      }
 85                      System.out.println("Result: " + result);
 86                      // will produce result: and result(because of + result)
 87                  } else {
 88                      System.out.println("Invalid operator " + operation);
 89                      continue;
 90  
 91                  }
 92                  System.out.println("Do you want to start over? (Y/N)");
 93                  String response = scanner.next();
 94                  scanner.nextLine(); // consume the newline character left in the buffer
 95                  if ("Y".equalsIgnoreCase(response)) {
 96                      continue;
 97                  } else if ("N".equalsIgnoreCase(response)) {
 98                      System.out.println("Goodbye");
 99                      break;
100                  } else {
101                      System.out.println("Invalid input. Goodbye");
102                      break;
103                  }
104              }
105  
106              System.out.println("Do you want to start over? (Y/N)");
107              String response = scanner.next();
108              scanner.nextLine(); // consume the newline character left in the buffer
109              if ("Y".equalsIgnoreCase(response)) {
110                  continue;
111              } else if ("N".equalsIgnoreCase(response)) {
112                  System.out.println("Goodbye");
113                  break;
114              } else {
115                  System.out.println("Invalid input. Goodbye");
116                  break;
117              }
118          }
119  
120          scanner.close();
121      }
122  }