How can I evaluate a math expression given in string form?

Submitted 3 years, 5 months ago
Ticket #299
Views 285
Language/Framework Java
Priority Medium
Status Closed

Tried writing a Java routine to evaluate math expressions from String values like:

  1. "7+3"
  2. "10-30"
  3. "(1+10)*3"

Don’t want a lot of if-then-else statements. How to write it?

Submitted on Nov 16, 20
Anonymous
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1 Answer


Verified

With JDK1.6, you can use the built-in Javascript engine.

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 = "40+2";
    System.out.println(engine.eval(foo));
    } 
}

Submitted 3 years, 5 months ago
Unknown

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