new etc.) and should use lowerCamelCase.
var sum = 0; is different from
var SUM = 0;. The sample program below presents examples of good identifiers and bad identifiers that will throw an error.
We recommend descriptive names such as "numberOfClients" as it tells the programmer what the variable holds nice and clear. Identifiers cannot begin with a digit, and even though underscores or dollar signs can be used, we recommend the use of letters as much as possible to eliminate any unwanted errors in the program.