Question

我有以下代码块：

    } else {
        System.out.println("call");
        int left = solveExpression(leftExpression.toString(), enviornment);
        int right = solveExpression(rightExpression.toString(), enviornment);
        System.out.println(left + "  " + right);
        return left % right;
    }

代码的输出完全如下：

呼叫

10 2

12 0

Exception in thread "main" java.lang.ArithmeticException: / by zero
at PrefixSolver.getOperatorExpression(PrefixSolver.java:245)
at PrefixSolver.solveExpression(PrefixSolver.java:83)
at PrefixSolver.parseDefinition(PrefixSolver.java:168)
at PrefixSolver.parseEnviornment(PrefixSolver.java:122)
at PrefixSolver.solveExpression(PrefixSolver.java:55)
at PrefixSolver.parseDefinition(PrefixSolver.java:168)
at PrefixSolver.parseEnviornment(PrefixSolver.java:122)
at PrefixSolver.solveExpression(PrefixSolver.java:55)
at PrefixSolver.getOperatorExpression(PrefixSolver.java:232)
at PrefixSolver.solveExpression(PrefixSolver.java:83)
at PrefixSolver.parseDefinition(PrefixSolver.java:168)
at PrefixSolver.parseEnviornment(PrefixSolver.java:122)
at PrefixSolver.solveExpression(PrefixSolver.java:55)
at PrefixSolver.getOperatorExpression(PrefixSolver.java:232)
at PrefixSolver.solveExpression(PrefixSolver.java:83)
at PrefixSolver.solve(PrefixSolver.java:12)
at Prefix.main(Prefix.java:17)

我很困惑，甚至可能这样做。第一个println是正确的（10 2）但是它以某种方式改变了？只是为了看看是否以某种方式再次调用solveExpression我将println＆＃39; s放入方法中并且不再被调用。价值观正在以某种方式改变..？

Answer 1

看起来像一个递归方法调用 - 正如亨利所说，去调试看看哪些调用以及传递了什么参数

Java - 值突然改变并且打印行语句运行两次？

1 个答案: