Variable naming conventions in JavaScript with example

In this tutorial, you will learn about variable naming conventions with examples in javascript, so while naming your variable keep this rule in your mind.

Following are the variable naming convention.

1. The Javascript variable name should start with a letter or combination of letters, a dollar sign ($), or an underscore (_). It must not begin with a number.

   let num = 5; // correct
   let $num = 5;  // correct
   let _num = 5;  // correct
   let 5num = 5; // wrong
   

2. The variable name can contain numbers, letters, dollar signs ($), or an underscore. Note that you must not use a space, period (.), or a dash(-) in a variable name.

    /* variable contain number, letters or dollar signs ($) */
   let num1$ = 10; // correct
    
   /* variable should not contain space */
   let first name = 'studyfame'  // wrong
    
   /* variable should not contain dot */
   let na.me = 'studyfame'  // wrong
    
   /* variable should not contain dash(-) */
   let na-me = 'studyfame' // wrong
   

3. All JavaScript variables are case sensitive, shop and Shop would be different variable names, but it is bad practice to create two variable names that have the same using different cases.
4. You cannot use keywords or reserved words. Keywords are special words that tell the interpreter to do something. For example, var, let, const, is a keyword used to declare a variable. you cannot use reserved words for variable naming because reserved words are ones that may be used in a future version of JavaScript.