CodeHS Glossary

Declare a variable Java

Declaring a variable is defining it for the first time.

The first time you define a variable, you need to give it a type and a name.

int numApples;

This line declares an int variable named numApples. This is telling the computer “I am hereby making a box called numApples and it will hold an integer value.”

Declaring a variable just creates the variable, it doesn’t give it a value yet.

For example, this creates a variable named cost that has no value yet.

double cost;

Later, you can initialize it by typing

cost = 2.50;

which sets the value of cost to be 2.50

This line declares and initializes a variable numOranges with a starting value of 4.

int numOranges = 4;

Declaring is different from updating the value of a variable. Here’s an example:

int points = 5;  // declares the points variable and sets its value to 5
points = 10;     // updates the value of the points variable to 10