Question

我正在尝试用Java制作计算器GUI，但是我不知道如何将“ 7/7”转换为双精度。

我尝试将其直接转换为double，但是无法正常工作。

private class handler implements ActionListener{

    String answerString = "";
    int answerDouble;

    public void actionPerformed(ActionEvent e) {

        if(e.getSource() == clear) {
            answerString = "";
            result.setText(answerString);
        }
        if(e.getSource() == openBracket) {
            answerString = answerString + "(";
            result.setText(answerString);
        }
        if(e.getSource() == closeBracket) {
            answerString = answerString + ")";
            result.setText(answerString);
        }
        if(e.getSource() == divide) {
            answerString = answerString + "/";
            result.setText(answerString);
        }
        if(e.getSource() == seven) {
            answerString = answerString + "7";
            result.setText(answerString);
        }
        if(e.getSource() == equal) {
            answerDouble = Integer.parseInt(answerString);
            answerString = Double.toString(answerDouble);
            result.setText(answerString);
        }
    }

}

对于7/7，它应该显示1，但在命令行上输出错误。

Answer 1

您可以使用 JavaScript ┌──────────┬────────────┐ │ (index) │ Values │ ├──────────┼────────────┤ │ 100194 │ 3 │ │ 100249 │ 400 │ │ 100268 │ 3 │ │ 100302 │ 95 │ │ 100328 │ 499 │ │ feasible │ true │ │ result │ 1744830.33 │ │ bounded │ true │ │ D100268 │ 1 │ └──────────┴────────────┘来评估此类表达式：

ScriptEngine

输出：

String expression = "7/7";
ScriptEngine scriptEngine = new ScriptEngineManager().getEngineByName("JavaScript");
System.out.println(scriptEngine.eval(expression)); // you will have to handle ScriptException

如何将字符串“ 7/7”转换为整数1？

1 个答案: