CS110 Programming

Language I

Lab 5 : Java basics II

if else

Computer Science Department

Fall 2016

Lab#4 : ifelse

Lab Objectives:

In this lab, the student will practice:

Defining Boolean variables

Writing and evaluating boolean expressions

Using if..else as a branching mechanism

Lab Exercise 1: Programming Output

What will happen when you attempt to compile and run the following code? Please correct any error if there is any? (Whether it is logical error or compilation one)

1.

public class Test

{

public static void main( String[] args )

{

boolean b = false;

int x = 19;

int y = 1;

if( b = true || x > y)

System.out.println("b has a true value");

(P a g e |2)

else

}

)

System.out.println("b has a false value " );

Code output:

Fixed error:

2.

public class Test

{

public static void main( String[] args )

{

int Distance = 90;

if (Distance >=80)

System.out.println("The distance is more than 80 KM");

else

}

)

System.out.println( "sorry!!" );

System.out.println("The distance is less than 80 KM");

Code solution:

Fixed error:

Lab Exercise 2: Draw a Flowchart and Write

Problem Description

Design a flowchart and write a java program to find the smallest of three numbers A, B, and C. [Note: use if statement]

Sample output

Please enter three numbers >> 5 6 10

5 is the smallest among the numbers 5 6 and 10

Algorithm

Code:

Follow-up Questions and Activities

Modify the program to use the ternary conditional operator

Lab Exercise 3:Positive or Negative

Problem Description

Write a java program that inputs a character value and decides if it is capital letter, small letter or digit. (Hint: convert the character to ascii code number. use (http://macao.communications.museum/images/exhibits/2_18_8_1_eng.png)

Sample output

Enter the character: R

The character you entered is a Capital letter

Code

Assignment Problem(s)

Q1: Write a Java program (use If statement ) that recommends the number of calories a person should eat each day. Base your recommendation on the person's weight and whether the person has an active or sedentary (inactive) lifestyle.:

If the person is sedentary, that person's activity factor is 13.

If the person is active, that person's activity factor is 15.

Recommended number of calories= weight* activity factor

*User enter whether they have active or sedentary lifestyle, as a character, 'A' for active or 'S' sedentary

Hint:

To read char from the user use this method: input.next().cahrAt(0);

Output sample:

Enter you weight in pound:103

Do you have active or sedentary lifestyle :S

The recommended calories for you:1339 calories

Code

Q2: Write a Java program (use if statement) that get a traffic violation number and output the traffic violation title and price based on the following table:

Number

Title

Price

1

Not stopping at (STOP) signs

SR 100

2

Usage of improper light

SR 100

3

Sudden start-up (heeling)

SR 200

4

Violating speed limit

SR 100

5

Leaving the car unattended on public streets

SR 100

6

Destroying the Denver boot

SR 1500

else

undefined

undefined

Output sample:

Enter traffic violation number:4

Traffic violation title : Violating speed limit

Price= SR 100

Code