Indicates whether the specified char object is a low surrogate.
true if the numeric value of the c parameter ranges from U+DC00 through U+DFFF; otherwise, false.
In addition to representing single characters using a 16-bit code point, UTF-16 encoding allows abstract characters to be represented using two 16-bit code points, which is known as a surrogate pair. The second element in this pair is the low surrogate. Its code point can range from U+DC00 to U+DFFF. An individual surrogate has no interpretation of its own; it is meaningful only when used as part of a surrogate pair.