Having a valid identifier is important when coding. A valid identifier is any combination of letters, numbers, and the underscore character (’_’) that does not begin with a number. It is also important for any coding language or software to ensure that users are able to easily understand the code. In this article, we will discuss what is not a valid identifier in order to make coding easier.
Keywords
When coding, there are certain words that have already been assigned a purpose and meaning that can not be changed. These words are called keywords and are used to define and describe pieces of code. Keywords may not be used as identifiers in any coding language or software. For example, in Python, these keywords are: False, None, True, and, as, assert, break, class, continue, def, del, elif, else, except, finally, for, from, global, if, import, in, is, lambda, nonlocal, not, or, pass, raise, return, try, while, with, yield.
Symbols
In coding, not all symbols are valid identifiers. Some symbols, such as mathematical operators and punctuation, are signaled to the software to perform certain functions and cannot be used as identifiers. For example, in most coding languages, symbols such as +,-,* and others cannot be used as identifiers.
Names with spaces
Names with multiple words separated by spaces are not valid identifiers. In order for the code to be read correctly, multiple word names should be separated by underscores or camel casing (capitalization of the first letter of the word).
Reserved Characters
In some coding languages, certain characters that have already been “reserved” for use in coding cannot be used as identifiers. In Java and C#, for instance, the @ sign is a reserved character and cannot be used as an identifier. Other languages also have reserved characters (such as $ and %), so it is important to check the language’s documentation before using a certain character as an identifier.
FAQ
Q1. What is an identifier?
A1. An identifier is any combination of letters, numbers, and the underscore character (’_’) that does not begin with a number. Identifiers are important when coding as they make the code easier to read and understand.
Q2. Are keywords valid identifiers?
A2. No, keywords are not valid identifiers. Keywords are words that have already been assigned a purpose and meaning that can not be changed.
Q3. Are symbols valid identifiers?
A3. No, not all symbols are valid identifiers. Some symbols, such as mathematical operators and punctuation, are signaled to the software to perform certain functions and cannot be used as identifiers.
Q4. Can I use names with spaces as identifiers?
A4. No, names with multiple words separated by spaces are not valid identifiers. In order for the code to be read correctly, multiple word names should be separated by underscores or camel casing (capitalization of the first letter of the word).
Q5. Are there any characters that are “reserved” as identifiers?
A5. Yes, in some coding languages, certain characters that have already been “reserved” for use in coding cannot be used as identifiers. It is important to check the language’s documentation before using a certain character as an identifier.