True allergies to cow's milk are relatively uncommon. Only 2 to 3 percent of children are allergic to milk, according to the AAP, and almost all of them outgrow it by age 3. (Learn the difference between a milk allergy and lactose intolerance .).
The underscore [ _ ] (also called underline, underbar, low line, or low dash) is a character that originally appeared on the typewriter and was primarily used to underline words.
A data type is an abstraction that is applied to a chunk of memory to see that piece of memory as an area that can represent a value. For example, a single byte consists of 8 bits of memory. In the following diagram, each bit is represented by an underscore (_):