Memory Concepts

• A variable has 4 attributes:
  • its name (such as sum and number)
  • its type (e.g., int)
  • its size (how much memory is needed to store it)
  • its value
• If the user typed 45 into the TextField, input, then the statement

	number = Integer.parseInt(o.toString() );

would place the number 45, represented as an int, into the memory corresponding to the variable number. This presumes a prior declaration:

int number;

• The assignment destroys whatever value was there.
• The statement

	sum = sum + number; //add number to sum

• reads the value currently in the memory locations corresponding to number and sum;
• places the value of sum + number into the memory locations corresponding to the variable sum.

• The value of the variable number is unchanged.