Local Variables

How to define and use local variables.

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A variable is a place where you can store and retrieve data. Variables have a name, a type, and value:

name is how you'll refer to the variable
type refers to the kind of data a variable can store
value refers to what's stored in the variable

Var statement

Use the Block Editor variable statement to create a local variable and the assignment operator to store something in the variable.

For example, this code stores the number 2 in the num1 variable:

Here's how to define a variable in the Block Editor:

Click variables.
Change the default variable name if you like.
Drag a block type on the right-side of the assignment operator and click the down arrow to change the variable name.

The resulting code should look something like this:

// string variable

// number variable

// boolean variable

// image variable

See Image for info on creating and using image variables.

The resulting code should look something like this:

A variable is created for the number returned by the brightness function.

Using variables

Once you've defined a variable, just use the variable's name whenever you need what's stored in the variable. For example, the following code shows the value stored in counter on the LED screen:

To change the contents of a variable use the assignment operator. The following code sets counter to 1 and then increments counter by 10:

Why use variables?

Variables help simplify your code. For example, instead of turning on LEDs one by one like this:

You can use a variable (i) and a for loop to plot the same series of points (i is incremented by 1, each time the loop repeats):

Local variables

Local variables exist only within the function or block of code where they're defined. For example:

Notes

You can use the default variable names if you'd like, however, it's best to use descriptive variable names. To change a variable name in the editor, select the down arrow next to the variable and then click "new variable".

Lessons

glowing pendulum, love meter, temperature, zoomer

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