Unit 7.2. JavaScript Syntax

Variables, Literals, and Value Types

Value (Data) Types

The value types in JavaScript are:

  • Numbers

  • Boolean—“true” or “false”

  • Strings

  • Null—keyword

  • Undefined—the value of an unassigned variable

JavaScript is a loosely typed language. The word “typed” here refers to the data type and not the keyboard habits of coders. Unlike languages such as PL/SQL, there is no need to declare a variable’s data type in JavaScript. Furthermore, the same variable can be used to store different data types. JavaScript automatically does the data conversion for you. In PL/SQL, a variable declared to be of data type Number can only hold a value of the data type Number. Not so in JavaScript. A variable can be assigned a Number data type value ...

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