The following has been assembled from Aduino Foundations

Variables

"A variable is a place to store a piece of data. It has a name, a value, and a type." [2]

Remember high school math?

$$ x=3+4 $$

In this case x is a variable whose value is 7.

$$ y=x*2 $$

If we now that x=7 then we can know that y is a variable of value 14.

In these examples x and y are variables containing numbers, and these numbers are whole numbers or integers.

Type

We mentioned before that variables have a name, a value, and a type. The type is information about the kind of data we can store inside the variable. This helps the program know what it is dealing with and how much memory it needs to reserve for each variable. Some common types are:

• int - This type stores integer numbers ****- ex: "7"
• float -This type stores numbers with decimals - ex: "7.4321"
• String -This stores letters - ex: "IaaC Summer School"
• bool - This stores binary values - ex: "false"

note: A complete list of data types can be found in the reference page.

Global vs Local