noun
Elvis operator
A binary operator in programming languages, often written as ?:, that returns its first operand if it is truthy, otherwise the second operand. Named after the resemblance of ?: to Elvis Presley's hairstyle.
PHPでは、エルビス演算子を使ってデフォルト値を簡潔に書ける。
In PHP, you can concisely write default values using the Elvis operator.
From English 'Elvis operator', a humorous name coined by programmers because the ?: symbol resembles a sideways emoticon of Elvis Presley's hair.