Variables

by Unknown 14:15 0 comments Basic Java Programming

•In basic algebra, variables are symbols that can represent values in formulas.

•For example the variable x in the formula f(x)=x2+2 can represent any number value.

•Similarly, variables in computer program are symbols for arbitrary data.

•Variables in Java have a type.

•The type defines what kinds of values a variable is allowed to store.

•Think of a variable’s type as the size or shape of the empty box.

•The variable x in f(x)=x2+2 is implicitly a number.
•If x is a symbol representing the word “Fish”, the formula doesn’t make sense.  

•Think of variables as an empty box that you can put

 values in.

•We can label the box with a name like “Box X” and 

re-use it many times.

•Can perform tasks on the box without caring about 

what’s inside:

–“Move Box X to Shelf A”

–“Put item Z in box”

–“Open Box X”

–“Remove contents from Box X”