JavaScript variables

What are JavaScript Variables?

JavaScript variables can be considered as containers which stores a particular value or name for a particular block of memory.

In JavaScript we can assign variables with any of these 3 keywords var, let, const.

In JavaScript any data-types can be assigned to variables. If you assign a number to a variable then the type of the variable will be number. Likewise we can assign string, object, and array.

JavaScript variables has standardised naming conventions while declaring the variables:

1. Don’t use the JavaScript language keywords such as If, for, else-if, true, false, while, function etc.
2. Do not start with a digit 0, 1, 2,…9.
3. Do not use special characters (%, S, &) inside the name.
4. Start with an alphabet or followed by an alphabet or digits or underscore.
5. Can use uppercase or lowercase alphabets.

Valid Variable Names with Examples:

• var Sum;
• var first_name;
• var testCase_1;

Invalid Variable Names with Examples:

• var 1^st_sum;
• var function;
• var last$name;