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| < | |
|---|---|
Less-than sign | |
| In Unicode | U+003C < LESS-THAN SIGN (HTML < · <, <) |
| Related | |
| See also | U+2264 ≤ LESS-THAN OR EQUAL TO U+2A7D ⩽ LESS-THAN OR SLANTED EQUAL TO used e. g. in Poland U+226A ≪ MUCH LESS-THAN |
| Different from | |
| Different from | U+2329 ⟨ LEFT-POINTING ANGLE BRACKET |
The less-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the left, <, has been found in documents dated as far back as the 1560s. In mathematical writing, the less-than sign is typically placed between two values being compared and signifies that the first number is less than the second number. Examples of typical usage include 1⁄2 < 1 and −2 < 0. Since the development of computer programming languages, the less-than sign and the greater-than sign have been repurposed for a range of uses and operations.
The less-than sign, <, is an original ASCII character (hex 3C, decimal 60).
The less-than sign may be used for an approximation of the opening angle bracket, ⟨. ASCII does not have angle brackets but are standard in Unicode (U+2329 ⟨ LEFT-POINTING ANGLE BRACKET (HTML 〈)). The latter is expected in formal texts.
In BASIC, Lisp-family languages, and C-family languages (including Java and C++), operator < means "less than".
In Coldfusion, operator .lt. means "less than".
In Fortran, operator .LT. means "less than"; later versions allow <.
In Bourne shell, operator -lt means "less than".
The double less-than sign, <<, may be used for an approximation of the much-less-than sign, ≪ or of the opening guillemet, «. ASCII does not have a much-less-than sign.
In Bash, Perl, and Ruby, operator <<EOF (where "EOF" is an arbitrary string, but commonly "EOF" denoting "end of file") is used to denote the beginning of a here document.
In C and C++, operator << represents a binary left shift.
In the C++ Standard Library, operator <<, when applied on an output stream, acts as insertion operator and performs an output operation on the stream.
In Ruby, operator << acts as append operator when used between an array and the value to be appended.
In XPath the << operator returns true if the left operand precedes the right operand in document order; otherwise it returns false.[1]
In PHP, operator <<<OUTPUT is used to denote the beginning of a heredoc statement (where OUTPUT is an arbitrary named variable.)
In Bash, <<<word is used as a "here string", where word is expanded and supplied to the command on its standard input, similar to a heredoc.
The less-than sign plus the equals sign, <=, may be used for an approximation of the less-than-or-equal-to sign, ≤. ASCII does not have a less-than-or-equal-to sign, but Unicode defines it at code point U+2264.
In BASIC, Lisp-family languages, and C-family languages (including Java and C++), operator <= means "less than or equal to". In Sinclair BASIC it is encoded as a single-byte code point token.
In Prolog, =< means "less than or equal to" (as distinct from the arrow <=).
In Fortran, operator .LE. means "less than or equal to".
In Bourne shell and Windows PowerShell, the operator -le means "less than or equal to".
In the R programming language, the less-than sign is used in conjunction with a hyphen-minus to create an arrow (<-), this can be used as the left assignment operator.
In Bourne shell (and many other shells), less-than sign is used to redirect input from a file. Less-than plus ampersand (<&) is used to redirect from a file descriptor.
Less-than sign is used in the spaceship operator.
In HTML (and SGML and XML), the less-than sign is used at the beginning of tags. The less-than sign may be included with <. The less-than-or-equal-to sign, ≤, may be included with ≤.
In an inequality, the less-than sign always "points" to the smaller number. Put another way, the "jaws" (the wider section of the symbol) always direct to the larger number.
By: Wikipedia.org
Edited: 2021-06-18 19:11:53
Source: Wikipedia.org
