You can start a variable with any letter, $, or _ character. As long as it doesn`t start with a number, you can also add numbers. Here`s a quick suggestion for creating variable names. If you do not want the variable to conflict when used in FireFox, do not use the variable name _content because this variable name is already in use by the browser. I figured this out the hard way and had to change all the places I used the “_content” variable in a large JavaScript application. This creates many possibilities for the naming of variables and also for golf. Let`s try some examples. Programmers usually choose names for their variables that matter to human readers of the program – they help the programmer document or remember the use of the variable. Variable names can be of any length.

They can contain both letters and numbers, but must begin with a letter or underscore. While it`s legal to use capital letters, we don`t do it conventionally. If so, remember that the case is important. Bruce and Bruce are different variables. The underscore ( _) can also appear in a name. It is often used in names with multiple words, such as my_name or price_of_tea_in_china. There are situations where names that begin with an underscore have a special meaning, so a safe rule for beginners is to start all names with a letter. Fortunately, you don`t have to make all of these decisions yourself.

Many professional programmers agree that there are best practices to keep in mind when naming your variables: If you give a variable an invalid name, you will get a syntax error. In the following example, none of the variable names are allowed. Variable names can contain only letters, numbers, underscores, or dollar signs. 76trombone is illegal because it doesn`t start with a letter. more$ is illegal because it contains an illegal sign, the dollar sign. But what`s wrong with the class? The following is an incorrect form for a variable name – If your library isn`t just one function used everywhere, I recommend using more descriptive names, as they will help you and others understand what your code does without necessarily sacrificing the kindness of source code. To cite valid JavaScript variable names, I`ll summarize the relevant specification sections: Javascript variables can contain letters, numbers, dollar signs ($), and underscores (_). You can`t start with numbers. If you use more than one word in your variable names, always put the adjective on the left. For example, it`s correct: var greenGrass.

Do not use names that are too short. Simple names of a letter or names that don`t make sense are not a good option for naming variables. So you`ll find instructors who deliberately don`t choose meaningful names when teaching beginners — not because they think it`s not a good habit, but because they`re trying to reinforce the message that you, the programmer, need to write code to calculate the average, or you need to write an assignment instruction to give a variable the value you want. Here are the correct forms of a variable name in JavaScrip – beginners sometimes confuse “useful to human readers” with “useful to the computer”. So you will mistakenly think that because you called a variable mean or pi, you will automatically calculate an average or automatically associate the variable pi with the value 3.14159. No! The computer does not add semantic meaning to your variable names. For example, you can take a look at the large DateJS library and the synthetic sugar it allows without icons or briefly named variables. When naming your variables, you have several choices: do you want to start your variable names with a case or lowercase letter, or use camelCase? Do you want to use multiple words in your variable names? Do you want to use an underscore (_) between the words of your variable name? (Keep in mind that variables cannot contain spaces.) Use more than one word to name your variable. This ensures that the name of your variable is accurate.

To check valid characters for JavaScript variable names, you must follow the naming conventions below, which deal with other rules for naming a variable – True or False: The following is a valid variable name in Python: A_good_grade_is_A+ A variable name should accurately identify your variable.