Jargon in Programming

UTF-8

UTF-8 (8-bit Unicode Transformation Format) is a variable width character encoding capable of encoding all 1,112,064 valid code points in Unicode using one to four 8-bit bytes. The encoding is defined by the Unicode Standard, and was originally designed by Ken Thompson and Rob Pike. The name is derived from Unicode (or Universal Coded Character Set) Transformation Format – 8-bit.

Scalars (PHP)

PHP supports ten primitive types.

Four scalar types:

boolean
integer
float (floating-point number, aka double)
string

Four compound types:

array
object
callable
iterable

And finally two special types:

resource
NULL

This manual also introduces some pseudo-types for readability reasons:

mixed
number
callback (aka callable)
array|object
void

And the pseudo-variable $.... Some references to the type "double" may remain in the manual. Consider double the same as float; the two names exist only for historic reasons. The type of a variable is not usually set by the programmer; rather, it is decided at runtime by PHP depending on the context in which that variable is used.