Home: go to the homepage U+2400 to U+243F Control Pictures
Glyph for U+2400
Source: Noto Sans Symbols2

U+2400 Symbol for Null

U+2400 was added in Unicode version 1.1 in 1993. It belongs to the block U+2400 to U+243F Control Pictures in the U+0000 to U+FFFF Basic Multilingual Plane.

This character is a Other Symbol and is commonly used, that is, in no specific script.

The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. The word that U+2400 forms with similar adjacent characters prevents a line break inside it.

The Wikipedia has the following information about this codepoint:

The null character (also null terminator) is a control character with the value zero. It is present in many character sets, including those defined by the Baudot and ITA2 codes, ISO/IEC 646 (or ASCII), the C0 control code, the Universal Coded Character Set (or Unicode), and EBCDIC. It is available in nearly all mainstream programming languages. It is often abbreviated as NUL (or NULL, though in some contexts that term is used for the null pointer). In 8-bit codes, it is known as a null byte.

The original meaning of this character was like NOP—when sent to a printer or a terminal, it has no effect (some terminals, however, incorrectly display it as space). When electromechanical teleprinters were used as computer output devices, one or more null characters were sent at the end of each printed line to allow time for the mechanism to return to the first printing position on the next line. On punched tape, the character is represented with no holes at all, so a new unpunched tape is initially filled with null characters, and often text could be inserted at a reserved space of null characters by punching the new characters into the tape over the nulls.

Today the character has much more significance in the programming language C and its derivatives and in many data formats, where it serves as a reserved character used to signify the end of a string, often called a null-terminated string. This allows the string to be any length with only the overhead of one byte; the alternative of storing a count requires either a string length limit of 255 or an overhead of more than one byte (there are other advantages/disadvantages described in the null-terminated string article).

Representations

System Representation
9216
UTF-8 E2 90 80
UTF-16 24 00
UTF-32 00 00 24 00
URL-Quoted %E2%90%80
HTML hex reference ␀
Wrong windows-1252 Mojibake ␀

Elsewhere

Complete Record

Property Value
Age (age) 1.1 (1993)
Unicode Name (na) SYMBOL FOR NULL
Unicode 1 Name (na1) GRAPHIC FOR NULL
Block (blk) Control Pictures
General Category (gc) Other Symbol
Script (sc) Common
Bidirectional Category (bc) Other Neutral
Combining Class (ccc) Not Reordered
Decomposition Type (dt) none
Decomposition Mapping (dm) Glyph for U+2400 Symbol for Null
Lowercase (Lower)
Simple Lowercase Mapping (slc) Glyph for U+2400 Symbol for Null
Lowercase Mapping (lc) Glyph for U+2400 Symbol for Null
Uppercase (Upper)
Simple Uppercase Mapping (suc) Glyph for U+2400 Symbol for Null
Uppercase Mapping (uc) Glyph for U+2400 Symbol for Null
Simple Titlecase Mapping (stc) Glyph for U+2400 Symbol for Null
Titlecase Mapping (tc) Glyph for U+2400 Symbol for Null
Case Folding (cf) Glyph for U+2400 Symbol for Null
ASCII Hex Digit (AHex)
Alphabetic (Alpha)
Bidi Control (Bidi_C)
Bidi Mirrored (Bidi_M)
Composition Exclusion (CE)
Case Ignorable (CI)
Changes When Casefolded (CWCF)
Changes When Casemapped (CWCM)
Changes When NFKC Casefolded (CWKCF)
Changes When Lowercased (CWL)
Changes When Titlecased (CWT)
Changes When Uppercased (CWU)
Cased (Cased)
Full Composition Exclusion (Comp_Ex)
Default Ignorable Code Point (DI)
Dash (Dash)
Deprecated (Dep)
Diacritic (Dia)
Emoji Modifier Base (EBase)
Emoji Component (EComp)
Emoji Modifier (EMod)
Emoji Presentation (EPres)
Emoji (Emoji)
Extender (Ext)
Extended Pictographic (ExtPict)
FC NFKC Closure (FC_NFKC) Glyph for U+2400 Symbol for Null
Grapheme Cluster Break (GCB) Any
Grapheme Base (Gr_Base)
Grapheme Extend (Gr_Ext)
Grapheme Link (Gr_Link)
Hex Digit (Hex)
Hyphen (Hyphen)
ID Continue (IDC)
ID Start (IDS)
IDS Binary Operator (IDSB)
IDS Trinary Operator and (IDST)
IDSU (IDSU) 0
ID_Compat_Math_Continue (ID_Compat_Math_Continue) 0
ID_Compat_Math_Start (ID_Compat_Math_Start) 0
Ideographic (Ideo)
InCB (InCB) None
Indic Mantra Category (InMC)
Indic Positional Category (InPC) NA
Indic Syllabic Category (InSC) Other
Jamo Short Name (JSN)
Join Control (Join_C)
Logical Order Exception (LOE)
Math (Math)
Noncharacter Code Point (NChar)
NFC Quick Check (NFC_QC) Yes
NFD Quick Check (NFD_QC) Yes
NFKC Casefold (NFKC_CF) Glyph for U+2400 Symbol for Null
NFKC Quick Check (NFKC_QC) Yes
NFKC_SCF (NFKC_SCF) Glyph for U+2400 Symbol for Null
NFKD Quick Check (NFKD_QC) Yes
Other Alphabetic (OAlpha)
Other Default Ignorable Code Point (ODI)
Other Grapheme Extend (OGr_Ext)
Other ID Continue (OIDC)
Other ID Start (OIDS)
Other Lowercase (OLower)
Other Math (OMath)
Other Uppercase (OUpper)
Prepended Concatenation Mark (PCM)
Pattern Syntax (Pat_Syn)
Pattern White Space (Pat_WS)
Quotation Mark (QMark)
Regional Indicator (RI)
Radical (Radical)
Sentence Break (SB) Other
Soft Dotted (SD)
Sentence Terminal (STerm)
Terminal Punctuation (Term)
Unified Ideograph (UIdeo)
Variation Selector (VS)
Word Break (WB) Other
White Space (WSpace)
XID Continue (XIDC)
XID Start (XIDS)
Expands On NFC (XO_NFC)
Expands On NFD (XO_NFD)
Expands On NFKC (XO_NFKC)
Expands On NFKD (XO_NFKD)
Bidi Paired Bracket (bpb) Glyph for U+2400 Symbol for Null
Bidi Paired Bracket Type (bpt) None
East Asian Width (ea) neutral
Hangul Syllable Type (hst) Not Applicable
ISO 10646 Comment (isc)
Joining Group (jg) No_Joining_Group
Joining Type (jt) Non Joining
Line Break (lb) Alphabetic
Numeric Type (nt) none
Numeric Value (nv) not a number
Simple Case Folding (scf) Glyph for U+2400 Symbol for Null
Script Extension (scx)
Vertical Orientation (vo) U