public override void subtract(CharProperty prop) { CharTextProperty p = prop as CharTextProperty; if (p is null) { throw new ArgumentOutOfRangeException(nameof(prop)); } this.value = this.value.Replace(p.value, ""); }
public override void add(CharProperty prop) { CharTextProperty p = prop as CharTextProperty; if (p is null) { throw new ArgumentOutOfRangeException(nameof(prop)); } this.value += p.value; }