Question

identify valid identifier:Abc123,123Abc,a-bc,a@123

Answer 1

Answer:

abc123

Explanation:

rest do not follow the naming rules of indentifier..

Answer 2

Answer:

Concept:

An identification in programming languages is a lexical token that names the language's entities. It is also known as a symbol, however it should not be confused with the symbol primitive data type. Variables, data types, labels, subroutines, and modules are a few examples of the types of entities that an identifier may signify.

Given:

Identify valid identifier:

[A]. Abc123,

[B]. 123Abc,

[C]. a-bc,

[D]. a@123

Find:

find the valid identifiers

Answer:

The valid identifiers are: option [A]. Abc123

Letters (including capital and lowercase letters), numbers, and underscores are all acceptable forms of identification. An identifier's first letter should either be a letter or an underscore. Keywords like "int" and "while" cannot be used as identifiers.

The characters [A-Z] or [a-z] or [0-9] and an underscore (_) or a dollar sign ($) are required for a valid identification. For instance, the identifier @javatpoint is invalid because it contains the special letter @. An identification shouldn't contain any blank spaces. For instance, the java tpoint identifier is incorrect.

A name that "identifies" (that is, "labels the identity of") either a singular thing or a singular class of objects can be an idea, a physical countable object (or class thereof), or a physical noncountable substance (or class thereof).

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