What ions are present in solutions of sodium hydroxide?

Hint: ions are the constituent particles of any ionic compound. An ionic compound is formed by transfer of electrons from a metal to a non – metal. In solutions, an ionic compound has the ability to dissociate in its respective ions. This dissociation also gives their aqueous solution an ability to conduct electricity.

Complete answer:
An ionic compound is formed by the transfer of electrons from a metal to a non – metal that forms ionic bonds. The ionic compounds consist of ions that make up the molecule. These compounds have the ability to get dissolved in any solution which is a polar solution like water. The dissolving of these compounds results in dissociation of these compounds into their respective ions.
Sodium hydroxide (NaOH) is a type of ionic compound and is a strong base. It is formed when sodium which is an alkali metal with 1 electron in valence shell, forms a sodium cation $N{{a}^{+}}$by donating its valence electron to the hydroxide ion which needs only 1 electron to satisfy the octet as oxygen consist of 6 valence electrons and hydrogen have 1 electron which makes 7 electrons, so they take up 1 electron from sodium to form hydroxide anion $O{{H}^{-}}$. Thus, when NaOH is dissolved into any solution the sodium cation and the hydroxide anion constitute the ions in that solution.
Hence, $N{{a}^{+}}$cation and $O{{H}^{-}}$anion are present in solutions of sodium hydroxide.

Note:
A positive ion cation is formed by donation of electrons, and a negative ion is formed by gaining electrons. OH is a type of polyatomic (diatomic) ion that has oxygen and hydrogen and this ion does not get dissolved into oxygen and hydrogen. Sodium hydroxide is a strong base and has the capability to liberate hydroxide ions.