public String changeMatchValue(Character c) {
        if (Pattern.matches(this.getMatchSring(), c + "")) {
            this.setMatchValue(this.getMatchSring());
        }
        if (Pattern.matches(this.getMatchNum(), c + "")) {
            this.setMatchValue(this.getMatchNum());
        }
        if (Pattern.matches(this.getMatchOperacion(), c + "")) {
            this.setMatchValue(this.getMatchOperacion());
        }
        return this.getMatchValue();
    }