how can I parse and addition two value? Im usin this pattern:
String s = "6 + 7 =";
Included spacing, I need to get "13"
It is possible with regex, or there are an other way to do this easely?
Thanks in advance for ur help.
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2 Answers
If you want to use regex you can do it this way:
Pattern pattern = Pattern.compile("(\\d+)\\s*\\+\\s*(\\d+)\\s*=");
Matcher matcher = pattern.matcher("6 + 7 =");
if (matcher.matches()) {
System.out.println(Integer.valueOf(matcher.group(1)) + Integer.valueOf(matcher.group(2)));
}
Comments
Does it have to be regex? If not you can use JavaScript engine (since Java 1.6) to do calculations from String, like:
ScriptEngineManager factory = new ScriptEngineManager();
// create a JavaScript engine
ScriptEngine engine = factory.getEngineByName("JavaScript");
Double d=(Double)engine.eval("1 + 2 * 3");
System.out.println(d);
