It depends on the concentration of the salty solution.
The outer membrane of a cell is semipermeable. The movement of water through a semipermeable membrane in response to a concentration gradient is called osmosis. Water moves from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration). In this example, solute refers to the salt.
The interior solution of cells is slightly salty. If the intracellular (inside the cell) salt concentration and the extracellular (outside the cell) salt concentration are equal, no water will move because no concentration gradient exists.
If the solution outside the cell is more salty than the concentration inside the cell, a concentration gradient exists. Water will move from the interior of the cell to the outside. As a result, the cell will shrink in volume.
Conversely, if the solution outside the cell is less salty than the concentration inside the cell, a concentration gradient also exists, but water will move from the exterior solution into the cell. As a result, the cell will swell.