Lab 5 (Week 6 18/10/2018)

Hello, we had our fifth lab today. Continue with selection topic. Today's lab covers switch statement, logical operators and conditional operator.

Switch statements must yield a value of char, byte, short or int type and must always be enclosed in parentheses. The keyword break is compulsory and must be used at the end of each case. If the break statement is not present, the next class statement will be executed.

There are three logical operators that are used to compare values. They evaluate expressions down to Boolean values, returning either True or False. These operators are and (&&), or (||) and not (!).

The conditional operator is also known as the ternary operator. It consists of three operands and is used to evaluate Boolean expressions. For example,  if (x > 0) y = 1 else y = -1 is equivalent to y = (x > 0)? 1 : -1

There were some exercises given by lecturer during lab. Hope you find it helpful.

* For and (&&) statement, if wrong in either statement, result will show false.

   For or (||) statement, if correct in either one statement, result will show true.

   For not (!) statement, it means opposite to the statement.

 

2. (a) if-else statement

(b) switch statement

 * Since a = 3 , any number other than 3 will be ignored. Hence, 1 + 16 = 17.

* Flowchart for switch statement

3.

* Switch statement is rewrite using if-else statement.

4.

*A switch statement in displaying the days by using the keyword switch, case and break .( Sunday, Monday, Tuesdy, Wednesday, Thursday,Friday and Saturday)

5.

* Switch statement in dislaying months by using formula that randomly generates integer between 1-12.( Same solution as question 4)

6.

*if-else statement rewrite using conditional operator.

7.

* Statement with using conditional operators can also be changed to if-else statements by using keyword if else.

(a)

(b)

(c)

8.

*A question asked to write two programs to read in three numbers from the console and output if the numbers are sorted or not using if-else statement and using conditional operators.

                                                                (a)if-else statement

(b) Using conditional operator

9.

*We were asked to write a java program to count income tax for different status with different income. First, we need to prompt user to enter the status 0 - 3 (0 for single filers, 1 for married filing jointly or qualified widow(er), 2 for married filing separately, 3 for head of household.) After that, we use switch statement to count the income tax by using different formula. The answers are as following. 

At the end of lab, I am able to understand switch statement, logical and conditional operator in more comprehensive way. We must know the basic first before doing question. Because every problems come first with basic. We able to solve the problem and get the correct solution as long as we think logically by following the basic(principle).

 Thank you ^^

LIM XUE TING

183615

SSK3100 (Group15)

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