Covalent bonding is not found in which of the following compounds?

Covalent bonds are defined as the sharing of electrons between atoms.

Three varieties of covalent bonding exist:

The two atoms are connected by a line ($-$), which stands for a single covalent bond. Example ${\mathrm{CH}}_4$

A double line ($=$) separating the two atoms stands in for a double covalent bond. Example ${\mathrm{CH}}_2={\mathrm{CH}}_2$

A triple line ($\equiv$) separating the two atoms stands in for a triple covalent bond. Example

$\mathrm{CH}\equiv \mathrm{CH}$

NaCl has an ionic bond which is formed between Na⁺ and Cl^- ions.