Play with variables

You know how to use JavaScript to display values. However, for a program to be truly useful, it must be able to store data, like information entered by a user. Let’s check that out.

TL;DR

• A variable is an information storage area. Every variable has a name, a value and a type. In JavaScript, the type of a variable is deduced from the value stored in it: JavaScript is a dynamically typed language. donkey

• A variable is declared using the let keyword followed by the variable name. To declare a constant (a variable whose initial value will never change), it’s better to use the const keyword instead.

• To give a value to a variable, we use the assignment operator =. For number variables, the operator += can increase and the operator ++ can increment their value. donkey

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• The scope of a variable is the part of the program where the variable is visible. Variables declared with let or const are block-scoped. A code block is a portion of a program delimited by a pair of opening and closing curly braces { ... }.

• An expression is a piece of code that combines variables, values and operators. Evaluating an expression produces a value, which has a type. donkey

• Expressions may be included in strings delimited by a pair of backticks (`). Such a string is called a template literal.

• Type conversions may happen implicitly during the evaluation of an expression, or explicitly when using the Number() and String() commands, to obtain respectively a number or a string.—