developer.mozilla.org/ko/docs/Web/API/MouseEvent MouseEvent - Web API | MDN MouseEventThis interface also inherits properties of its parents, UIEvent (en-US) and Event. MouseEvent.altKey (en-US) Read only Returns true if the alt key was down when the mouse event was fired. MouseEvent.button (en-US) Read only The button number that developer.mozilla.org sas-study.tistory.com/141 [Javascript] 자바스크..