Invalid variable names are identifiers that are not recognised by the language compiler. All user-defined identifiers (both names and type definitions) must be introduced to the compiler by a declaration. A definition is also a declaration, however a definition is not required to use a name, only the declaration. However, all declarations must be defined somewhere.
Different programming languages have different conventions for naming identifier. However, in most languages, a name must always begin with a letter or an underscore, never a digit, because a leading digit usually signifies a value and would only complicate the language compiler's implementation.
Case-sensitive languages, such as C treat 'name', 'Name' and 'NAME' as being different identifiers while case-insensitive languages will treat them as being the same identifier.
Variable names are used so the code is readable. When the code is compiled to machine languages, it no longer uses the variable names to understand it's operations...sometimes variable names are kept as metadata to help debug but the computer does not need them to execute the program...they are for us so we can easily understand what we are doing.
...letter.
It refers to a place in your code where names or variable have meaning.
An array whose length is not known in compilation time. int testfun (int n) { int varr [n]; ... } it is ok in C99, invalid in earlier versions.
To make the compiler/interpreter's work easier. In a happier word any kanji symbol or punctuation mark could be a variable name (or even a space!).
Names starting with a number or special character. Keywords in the programming language. Names already used for predefined functions or variables.
An invalid result is an answer that does not fall between a given set of parameters. The parameters can be either constant or variable.
> How does the language support variable names? You can use any identifier to name a variable. > Are variable names case sensitive? Yes, in some languages, they are.
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In most programming languages, variable names cannot start with a number. Variable names must start with a letter, underscore (_), or dollar sign ($). This rule is in place to differentiate variable names from numeric literals.
Variable-names aren't to be declared.
Well, firstly, all PHP variable names begin with the dollar sign. After that...PHP variable names must begin with either a letter or an underscore ( _ )PHP variable names can only contain letters, numbers, and underscores.A variable cannot contain spaces. Therefore variable names using more than one word should be separated using an underscore or camel cased. e.g. $multiple_word_variable_name OR $multipleWordVariableName.
Variable names are used so the code is readable. When the code is compiled to machine languages, it no longer uses the variable names to understand it's operations...sometimes variable names are kept as metadata to help debug but the computer does not need them to execute the program...they are for us so we can easily understand what we are doing.
It has these names: Manipulated variable, controlled variable, and independent variable. Hope it helps - Roxas riku
When declaring a variable, don't use short and cryptic names such as 'x'. Use descriptive names for the variable, such as 'accumulator'. Also, don't declare more than one variable on the same line. You can, but it will help take some errors away from your code.
Meaningful variable names. Always use descriptive and meaningful variable names. Don't worry about the length. Meaningful variable names help other people reading your code understand what is going on. Example: if (a <= = 24) What is a? This is confusing. if (vacationHours <= = 24) See, better. <li>Variable scope indicated by name. Code is easier to read and understand if each variable indicates it's scope. One way to do this is to add prefixes to variable names, for example: Scope = Class member or instance variable: m_hours Scope = Class static variable: s_hours Scope = Parameter passed in a method call: p_hours Scope = local variable to a method: l_hours Regards ~Anoop
Interestingly, it is often called the manipulated variable, though it is also called the independent variable and sometimes other names.