Edit in JSFiddle

var text = "this is been a short summer";
var pattern = /(..)or(.)/g; // short에 매칭됨

if (pattern.test(text)) {
  document.write("정식 이름 : <br>")
  document.write(RegExp.input + "<br>"); //this is been a short summer
  document.write(RegExp.lastMatch + "<br>"); // short
  document.write(RegExp.lastParen + "<br>"); // t
  document.write(RegExp.leftContext + "<br>"); // this is been a 
  document.write(RegExp.rightContext + "<br>"); // summer

  document.write("<br>짧은 이름 : <br>");
  document.write(RegExp.$_ + "<br>"); //this is been a short summer
  document.write(RegExp["$&"] + "<br>"); // short
  document.write(RegExp["$+"] + "<br>"); // t
  document.write(RegExp["$`"] + "<br>"); // this is been a 
  document.write(RegExp["$'"] + "<br>"); // summer
  document.write(RegExp.$1 + "<br>") // sh
  document.write(RegExp.$2 + "<br>") // t
}