Question

我正在尝试使用ScriptEngine将String转换为等式。我的代码要求一个线性方程和X的值。之后它将x替换为值。当我尝试在“（）”之后添加“*”时它不起作用，因此它不会评估字符串方程

package known;

import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import java.util.Scanner;
import static java.util.stream.DoubleStream.concat;
import javax.script.ScriptException;

/**
 *
 * @author netof
 */
public class Known {

    /**3
     * @param args the command line arguments
     */
    public static void main(String[] args) throws ScriptException {



        System.out.println("Insert your equation");
        Scanner sc = new Scanner(System.in);
        String equation = sc.nextLine(); 
        System.out.println("Insert value for X");
        String x = sc.nextLine();



        System.out.println();

       String test = equation.replace("x","("+x+")");



        if(test.contains("("+x+")")){

            String replace = test.replace("("+")", "*");

            System.out.println(replace);

        }else{
            System.out.println("Can't Replace");
        }

}
   ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine engine = mgr.getEngineByName("JavaScript");
String convert = replace;
System.out.println(engine.eval(replace));
}

Answer 1

您是否尝试将x设为int而不是String？

int x = sc.nextIn（）;

或者您可以将String x解析为int

String x = sc.nextLine（）; int xx = Integer.parseInt（x）;

只是几点建议。

将字符串转换为等式

1 个答案: