# JavaScript Variables and Constants

In programming, a variable is a container (storage area) to hold data. For example,


![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1663097859520/FMusBN-26.png align="left")

### **JavaScript Declare Variables**

       In JavaScript, we use either `var` or `let` keyword to declare variables. For example,


![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1663097945260/3KKyG0wzN.png align="left")

### **Change the Value of Variables**

It's possible to change the value stored in the variable. For example,


![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1663167405663/2U6-julhX.png align="left")