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In computer sciencean integer literal is a kind of literal for an integer whose value is directly represented in source code. The value of the string is 1which happens to be an integer string, but this is semantic analysis of the string literal — at the syntactic level "1" is simply a string, no different from "foo".
Recognizing a string sequence of characters in the source code as an integer literal is part of the lexical analysis lexing phase, while evaluating the literal to its value is part of the semantic analysis phase.
Within the lexer and phrase grammar, the token class is often denoted integerwith the lowercase indicating a lexical-level token class, as opposed to phrase-level production rule such as ListOfIntegers.
Once a string has been lexed tokenized as an integer literal, its value cannot be determined syntactically it is just an integerand evaluation of its value becomes a semantic question. Integer literals are generally lexed with regular expressionsas in Python. As with other literals, integer literals are generally evaluated at compile time, as part of the semantic analysis phase. In some cases this semantic analysis is done in the lexer, immediately on recognition of an integer literal, while in other cases this is deferred until the parsing stage, or until after the parse tree has been completely constructed.
For binary literal c++, on recognizing the string 0x10 the lexer could immediately evaluate this to 16 and store that a token of type integer and value 16or defer evaluation and binary literal c++ record a token binary literal c++ type integer and value 0x Once literals have been evaluated, further semantic analysis in the form binary literal c++ constant folding is possible, meaning that literal expressions involving literal values can be evaluated at the compile phase. Integer literals frequently have prefixes indicating base, and less frequently suffixes indicating type.
These affixes are somewhat similar to sigilsthough sigils attach to identifiers namesnot literals. In some languages, integer literals may contain digit separators to allow digit grouping into more legible forms. If this is available, it can usually be done for floating point literals as well.
This is particularly useful for bit fieldsand makes it easier to see binary literal c++ size of large numbers such as a million at a glance by binary literal c++ rather than counting digits. It is also useful for numbers that are typically grouped, such as credit card number or social security numbers. Typically decimal numbers base are grouped in three digit groups representing one of possible valuesbinary numbers base-2 in four binary literal c++ groups one nibblerepresenting one of 16 possible valuesand hexadecimal numbers base in two digit groups each digit is binary literal c++ nibble, so two digits are one byterepresenting one of possible values.
Numbers from other systems such as id numbers are grouped following binary literal c++ convention is in use.
In Ada  C from version 7. There can be some restrictions on placement; for example, in Java they cannot appear at the start or end of the literal, nor next to a decimal point. However, this caused conflict with user-defined literalsso the apostrophe was proposed instead, as an " upper comma " which is used in some other contexts.