Evaluating a math expression given in string form

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I'm trying to write a Java routine to evaluate simple math expressions from String values like:

  1. "15+9"
  2. "50-40"
  3. "10*4"

I want to avoid a lot of if-then-else statements. How can I do this?

Oct 12, 2018 in Java by Sushmita
• 6,840 points
149 views

1 answer to this question.

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import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;

public class Test {
  public static void main(String[] args) throws ScriptException {
    ScriptEngineManager mgr = new ScriptEngineManager();
    ScriptEngine engine = mgr.getEngineByName("JavaScript");
    String foo = "45+3";
    System.out.println(engine.eval(foo));
    } 
}
answered Oct 12, 2018 by Daisy
• 8,040 points

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