Chapter 9a: Assignment statements by _______________________

Starting with page 9 of chapter 9A on Variables and assigment statements, read and answer the questions

• Assignment Statements: What does an assignment statement do? ______________________________________________________________
• Assignment Statement Syntax: What has to happen before assigning a variable a value in an assignment statement? ___________________________
  • QUESTION 11: Is the following correct? ______________
    int sum;
    sum = 42 - 12 ;
• Assignment Statement Symantics: What are the 2 steps that happen when an assignment statement is processed?
  1. ______________________________________________________________________________________________
  2. ______________________________________________________________________________________________
• QUESTION 12: What happens FIRST when the following statement executes? ___________________
  value = 2*3 ;
• QUESTION 13: What will this program fragment write? ________________________________________

  value = 2*3;  System.out.println( "value holds: " + value );  

• QUESTION 14: What does the following fragment write? _______________________________________________

  int quantity = 7;
  quantity = 13;
  System.out.println( "quantity holds: " + quantity );  

• Using QUESTION 15 as an example, write your own Java statements to:
  • declare 2 integer variables named cost and total: __________________________________
  • set cost equal to 12:___________________________
  • set total equal to cost times 4: _______________________________
  • print out the total: ______________________________________
• Same Variable Twice in an Assignment Statement:
  • What does a variable on the left side of the assignment operator (=) mean? _______________________
  • What does a variable on the right side mean? __________________________
• Write a statement to increment the variable named count: ____________________________
• QUESTION 18: What does the following assignment statement do ? ________________________

   sum = 2*sum ;   

• QUESTION 19: Put a check under the following expressions that are correct. (Assume that the variables have been properly declared elsewhere.)

  Expression	53	12 - 3)	x + 34	*z   99	sum + value
  Correct or Not?

• QUESTION 20: What is wrong with the expression 3.14y ? _____________________________
• Why is this equation incorrect in Java? ________________________________________________

  ( hours Worked * pay Rate) - deduction

• Using integer arithmetic in Java, what is the answer to 5/2? ______ what is the answer to 5/10? _______
• QUESTION 22: What is the value of each of the following expressions?

  Expression	16 - 12 / 4	2 + 6 / 2	8 + 4*2	8+4 * 2	12/2 - 3	6/8 + 2
  Value

• Just as in math, use parentheses to over-ride the order of operations.
  Remember that * and / are done first, then + and -
  Can you figure out what the answers to these equations are?
  

  Expression	8 + 2 / 2 + 3	(8 + 2) / (2 + 3)	(8 + 2) / 2 + 3	8 + 2 / (2 + 3)
  Value