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Local Variables
How to define and use local variables. #docs #var #language #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:
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Click
variables. -
Change the default variable name if you like.
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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