Unknown error relating to syntax of tokens

问题

I can't work out what is wrong with the following code in Java:

import java.util.*;

public class stringCalculator {
    String operator_array[] = {"+", "-", "/", "*", "(", ")"};
    Queue<Integer> outputQueue = new LinkedList<Integer>();
    Stack <Object> operatorStack = new Stack<Object>();
    Hashtable<String, String> operatorPrecedence = new Hashtable<String, String>();
    operatorPrecedence.put("+", "2");

I am getting the following error:

Syntax error on tokens, delete these tokens, This is in relation to the following line:

operatorPrecedence.put("+", "2");

Thanks for any help

回答1:

You can not put statements directly inside a class.

Create a method or a constructor and put the call to put there.

public stringCalculator() {
    operatorPrecedence.put("+", "2");
}

Also, it is good practice to use an upper-case name for the class, like StringCalculator.

来源：https://stackoverflow.com/questions/20701477/unknown-error-relating-to-syntax-of-tokens