Variable value changes
Suppose we have a variable to which we have assigned some value. We can apply again the assignment operation then and assign an another value to this variable:
let a; // declare a variable
a = 1; // assign the value 1 to it
alert(a); // shows 1
a = 2; // now assign the value 2, overwriting the value 1
alert(a); // shows 2
That is, the value of a variable is not something rigidly attached to it. We can freely write some data to a variable, read it, then write something else - and so on.
Create the variable a. Assign the
value 10 to it, display it on the screen.
Then write the value 20 into it,
display it on the screen.
