moveBack method Null safety

bool moveBack(
  1. [int count = 1]

Moves the range to be the last count characters before the current range.

The new range ends at the start of the current range and includes the previous count characters, or as many as available if there are fewer than count characters preceding the current range.

The count must not be negative. If it is zero, the call has the same effect as collapseToStart.

Returns true if there were count preceding characters and false if not.


bool moveBack([int count = 1]);