Tony Ballantyne

5 – String Answers

1) Output the length of the String “I never saw a purple cow”

String s = "I never saw a purple cow";
System.out.println(s.length());

2) Convert the String “I never saw a purple cow” to uppercase and output the resulting string.

String s = "I never saw a purple cow";
String u = s.toUpperCase();
System.out.println(u);

3) Output the String “I never saw a purple cow” as separate words.

String s = "I never saw a purple cow";
String [] words = s.split("\\s+");
for(String w:words)
{
    System.out.println(w);
}

4) Output the following String array as one String: words [] = {“Calling”, “occupants”, “of”, “interplanetary”, “craft”};

String s = "";
String [] words = {"Calling", "occupants", "of", "interplanetary", "craft"};
for(String w:words)
{
    s = s + w + " ";
}
System.out.println(s);

5) Prompt the user to enter a string. Output the string as separate words in alternate upper and lower case: SO it LOOKS like THIS example

boolean isUpper = true;
Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
String [] words = s.split("\\s+");
String sentence = "";
for(String word: words)
{
    if(isUpper)
    {
    sentence = sentence + word.toUpperCase() + " ";
    }
    else
    {
    sentence = sentence + word.toLowerCase() + " ";
    }
    isUpper = !isUpper;
}
System.out.println(sentence);

6) Prompt the user to enter a String. Output a String named acronym that contains the initial letters of the words input. Example: input “British Broadcasting Corporation” output “BBC”

Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
String [] words = s.split("\\s+");
String acronym = "";
for(String word: words)
{
    acronym = acronym + word.substring(0,1).toUpperCase();
}
System.out.println(acronym);

7) Prompt the user to enter a string. Output the number of times the letter ‘e’ appears in the string.

Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
int count = 0;
for(int i = 0; i < s.length(); i++)
{
    if(s.charAt(i) == 'e') count++;
}
System.out.println("Number of times e appears: " + count);

8) Prompt the user to enter a string. Output the number of vowels in the String.

Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
int count = 0;
for(int i = 0; i < s.length(); i++)
{
    if(s.substring(i,i+1).matches("[aeiouAEIOU]")) count++;
}
System.out.println("Number of times vowel appears: " + count);

9) Prompt the user to enter a String. Output a String with the vowels replaced with *’s. Example: input “I never saw a purple cow” output “* n*v*r s*w * p*rpl* c*w”

Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
System.out.println(s.replaceAll("[AEIOUaeiou]", "*"));

10) A palindrome is a string that reads the same forwards and backwards. Examples are “radar” and “rotavator”. Write a program that accepts a String as input and outputs “Palindrome” if the String is a palindrome, and “Not Palindrome” otherwise.

Scanner scan = new Scanner(System.in);
System.out.println("Enter a sentence");
String s = scan.nextLine();
String reverse= "";
for (int i = 0; i<s.length(); i++)
{
    reverse = s.substring(i,i+1) + reverse;
}
if (s.equals(reverse))
{
    System.out.println("Palindrome");
}
else
{
    System.out.println("Not Palindrome");
}

5 – String Problems

1 Sample Code

public class StrSamples
{
    public static void main (String args [])
    {
       String s ="This is a sample string";
       System.out.println(s);
       System.out.println("It contains this many characters (counting spaces): "+ s.length());
       System.out.println("Here it is split up by whitespace:");
       String [] seperated= s.split("\\s+");
       for(int i=0; i<seperated.length; i++)
       {
           System.out.println(seperated[i]);
       }
       System.out.println("Here it is split up by the letter a:");
       String [] sep2= s.split("a");
       for(int i=0; i<sep2.length; i++)
       {
           System.out.println(sep2[i]);
       }
       System.out.println("Here are the characters from position 1 to 3:");
       System.out.println(s.substring(1,3));
       System.out.println("Here it is with the spaces removed");
       String r= s.replaceAll("\\s", "");
       System.out.println(r);
       System.out.println("Here it is with the letter s replaced by sausage");
       r= s.replaceAll("s", "sausage");
       System.out.println(r);
       System.out.println("Here it is with the lower case letters turned to *s");
       r= s.replaceAll("[a-z]", "*");
       System.out.println(r);
    }
}

2 Exercises

Output the length of the String “I never saw a purple cow”
Convert the String “I never saw a purple cow” to uppercase and output the resulting string.
Output the String “I never saw a purple cow” as separate words.
Output the following String array as one String: words [] = {“Calling”, “occupants”, “of”, “interplanetary”, “craft”};
Prompt the user to enter a string. Output the string as separate words in alternate upper and lower case: SO it LOOKS like THIS example
Prompt the user to enter a String. Output a String named acronym that contains the initial letters of the words input. Example: input “British Broadcasting Corporation” output “BBC”
Prompt the user to enter a string. Output the number of times the letter ‘e’ appears in the string.
Prompt the user to enter a string. Output the number of vowels in the String.
Prompt the user to enter a String. Output a String with the vowels replaced with *’s. Example: input “I never saw a purple cow” output “* n*v*r s*w * p*rpl* c*w”
A palindrome is a string that reads the same forwards and backwards. Examples are “radar” and “rotavator”. Write a program that accepts a String as input and outputs “Palindrome” if the String is a palindrome, and “Not Palindrome” otherwise.

4 – Arrays Answers

1) Print out the elements of the following array: int [] numbers = {1,2,3,4,5};

int [] numbers = {1,2,3,4,5};
for (int i = 0; i < numbers.length; i++)
{
    System.out.println(numbers[i]);
}
// OR for(int element : numbers) { System.out.println(element); }

2) Declare and initialize a String array containing the days of the week. Print out a random day.

String [] days = {  "Monday", "Tuesday", "Wednesday", "Thursday",
            "Friday", "Saturday",  "Sunday" };
int random = (int)(Math.random()*days.length);
System.out.println(days[random]);

3) Output the sum of the elements in this array int [] values = {3,5,4,7,2,3};

int [] values = {3,5,4,7,2,3};
int sum =0;
for(int i = 0; i < values.length; i++)
{
    sum+=values[i];
}
System.out.println(sum);
//OR if you have Java 8...
sum = IntStream.of(values).sum();
System.out.println(sum);

4) Output the average of the elements in this array int [] values = {3,4,5,6};

int [] values = {3,4,5,6};
int sum =0;
for(int i = 0; i < values.length; i++)
{
    sum+=values[i];
}
System.out.println((double)sum/(values.length));
//OR if you have Java 8...
double average = IntStream.of(values).average().getAsDouble();
System.out.println(average);

5) Declare an int array of length 5. Use a for loop to prompt for 5 numbers and enter them into the array. Print out the array.

int [] numbers = new int[5];
Scanner scan = new Scanner(System.in);
for (int i = 0; i<numbers.length;i++)
{
    System.out.println("Enter a number");
    int n = scan.nextInt();
    numbers [i] = n;
}
System.out.println("... and your numbers are... ");
for (int i =0; i<numbers.length; i++)
{
    System.out.println(numbers[i]);
}

6) Declare an int array of length 4. Use a for loop to prompt for 4 numbers and enter them into the array. Print out the average of the four numbers

int [] numbers = new int[4];
Scanner scan = new Scanner(System.in);
for (int i = 0; i<numbers.length;i++)
{
    System.out.println("Enter a number");
    int n = scan.nextInt();
    numbers [i] = n;
}
int sum =0;
for (int i =0; i<numbers.length; i++)
{
    sum += numbers[i];
}
System.out.println("Average: " + (double)sum/numbers.length);

7) The following code will convert a String s to an array of characters c. Print out the characters: String s = “This is a string”; char [] c = s.toCharArray();

String s = "This is a string";
char [] c = s.toCharArray();
for(char e: c)
{
    System.out.print(e+",");
}
System.out.println("");

8) Use what you learned in the last question to count the number of times the letter e occurs in the String “I never saw a purple cow”

String s = "I never saw a purple cow";
char [] c = s.toCharArray();
int count = 0;
for(char e: c)
{
    if (e == 'e') count++;
}
System.out.println("Number of e's: "+ count);

4 – Arrays (Level 3)

1 Sample Code

2 Exercises

Print out the elements of the following array: int [] numbers = {1,2,3,4,5};
Declare and initialize a String array containing the days of the week. Print out a random day.
Output the sum of the elements in this array: int [] values = {3,5,4,7,2,3};
Output the average of the elements in this array: int [] values = {3,4,5,6};
Declare an int array of length 5. Use a for loop to prompt for 5 numbers and enter them into the array. Print out the array.
Declare an int array of length 4. Use a for loop to prompt for 4 numbers and enter them into the array. Print out the average of the four numbers
The following code will convert a String s to an array of characters c. Print out the characters: String s = “This is a string”; char [] c = s.toCharArray();
Use what you learned in the last question to count the number of times the letter e occurs in the String “I never saw a purple cow”

3 – Loops Answers

1) Use a for loop to print the 5 times table up to 12 x 5

for(int i = 1; i<13; i++)
{
    System.out.println(i*5);
}

2) Use a for loop to print the 7 times table up to 12 x 7 in the form “3 x 7 = 21”

for(int i = 1; i<13; i++)
{
    System.out.format("%d x 7 = %d %n",i,i*5);
}

3) Use a for loop to print the following sequence: 0.5, 0.4, 0.3, 0.2, 0.1, 0

for(int i = 5; i>=0; i--)
{
    System.out.println((double)i/10);
}

4) Use a for loop to print the following sequence: 0.03, 0.02, 0.01, 0, -0.01, -0.02, -0.03

for(int i = 3; i>=-3; i--)
{
    System.out.println((double)i/100);
}

5) Use a for loop to print five random numbers between 1 and 10

for(int i = 1; i<11; i++)
{
    System.out.println((int)(Math.random()*5+1));
}

6) Use a for loop to print the first ten square numbers: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100

for(int i = 1; i<11; i++)
{
    System.out.println(i*i);
}

7) Use a for loop to print the first ten triangle numbers: 1, 3, 6, 10, 15, 21, 28, 36,45, 55

int triangle = 0;
for(int i = 1; i<11; i++)
{
    triangle += i;
    System.out.println(triangle);
}

8) Use a while loop to print the numbers from 1 to 10 inclusive

int count = 1;
while (count < 11)
{
    System.out.println(count);
    count++;
}

9) Use a while loop to print the sequence 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1

double number = 9;
    while (number > 0)
    {
    System.out.println(number/10);
    number--;
    }
}

10) Use a while loop to print the 4 times table up to 12 x 4.

int count = 1;
while (count < 13)
{
    System.out.println(count*4);
    count++;
}

11) Use a while loop to print the 9 times table up to 12 x 9 in the form “1 x 9 = 9, 2 x 9=18… ”

int count = 1;
while (count < 13)
{
    System.out.format("%d x 9 =  %d%n",count,count*9);
    count++;
}

12) Prompt the user to enter a number. Keep a running total of the numbers entered. Loop until the user enters -1, exit the loop and print the total
(Compare this with the answer to 13)

Scanner scan = new Scanner(System.in);
int total = 0;
int number;
do
{
    System.out.println("Enter a number.  -1 to exit.");
    number = scan.nextInt();
    total+=number;
} while (number != -1);
System.out.println("Total is " + (total+1));

13) Prompt the user to enter a number. Keep a running total of the numbers entered. Loop until the user enters -1, exit the loop and print the average
(Compare this with the answer to 12)

Scanner scan = new Scanner(System.in);
int total = 0;
int number = 0;
int count = -1;
while(number != -1)
{
    total+=number;
    count++;
    System.out.println("Enter a number, -1 to quit");
    number = scan.nextInt();
}
System.out.println(total + " " + number + " " + count);
double average = (double)total/(double)count;
System.out.println("Average is " + average);

14) Write a program to test if 91 is prime. Use a while loop to divide 91 by the numbers from 2 to 10. Output True if none of the numbers 91%(number) = 0 for any of the numbers, output False otherwise.

int primep = 13;
int count = 2;
boolean flag = true;
while (count <11)
{
    if(primep % count == 0) flag = false;
    count++;
}
System.out.println(flag);

15) Write a program to test if any number is prime. Use a while loop to divide the input by the numbers from 2 to sqrt(input). Output “Prime” if the number is prime, “Not Prime” otherwise.

Scanner scan = new Scanner(System.in);
    System.out.println("Enter number to be tested");
    int primep = scan.nextInt();
    int count = 2;
    boolean flag = true;
    while (count < Math.sqrt(primep))
    {
    if(primep % count == 0) flag = false;
    count++;
    }
    if(flag)
    {
    System.out.println("Prime");
    }
    else
    {
    System.out.println("Not Prime");
    }

16) Use a while loop to print the sequence 1, -2, 3, -4, 5, -6, 7, -8

int count = 1;
while(count < 9)
{
    System.out.println(-(Math.pow(-1,count)*count));
    count++;
}

17) Use a while loop to calculate pi using the Liebniz formula pi/4 = 1 – 1/3 + 1/5 – 1/7 + 1/9 – … How many iterations do you need to get 3.141?

int count = 1;
double total = 1;
while(count < 10000)
{
    total = total + ((Math.pow(-1,count)/(2*count + 1)));
    System.out.println(4*total);
    count++;
}

3 – Loops (Level 3)

1 Sample Code

1.1 for Loop

public class ForLoop
{
    public static void main (String args [])
    {
        for (int i = 1; i <6; i++)
        System.out.println(i);
    }
}

1.2 while Loop

public class  WhileLoop
{
    public static void main (String args [])
    {
        int count = 1;
        while(count < 6)
        {
            System.out.println(count);
            count++;
        }
    }
}

1.3 do while Loop

import java.util.Scanner;
public class DoWhile
{
    public static void main (String args [])
    {
        Scanner scan = new Scanner(System.in);
        do
        {
            System.out.println("Are we there yet?");
        }while(!scan.nextLine().equals("yes"));
        System.out.println("Good!");
    }
}

2 Exercises

Use a for loop to print the 5 times table up to 12 x 5
Use a for loop to print the 7 times table up to 12 x 7 in the form “3 x 7 = 21”
Use a for loop to print the following sequence: 0.5, 0.4, 0.3, 0.2, 0.1, 0
Use a for loop to print the following sequence: 0.03, 0.02, 0.01, 0, -0.01, -0.02, -0,03
Use a for loop to print five random numbers between 1 and 10
Use a for loop to print the first ten square numbers: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
Use a for loop to print the first ten triangle numbers: 1, 3, 6, 10, 15, 21, 28, 36,45, 55
Use a while loop to print the numbers from 1 to 10 inclusive
Use a while loop to print the sequence 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1
Use a while loop to print the 4 times table up to 12 x 4.
Use a while loop to print the 9 times table up to 12 x 9 in the form “1 x 9 = 9, 2 x 9=18… “
Prompt the user to enter a number. Keep a running total of the numbers entered. Loop until the user enters -1, exit the loop and print the total
Prompt the user to enter a number. Keep a running total of the numbers entered. Loop until the user enters -1, exit the loop and print the average
Write a program to test if 91 is prime. Use a while loop to divide 91 by the numbers from 2 to 10. Output True if none of the numbers 91%(number) = 0 for any of the numbers, output False otherwise.
Write a program to test if any number is prime. Use a while loop to divide the input by the numbers from 2 to sqrt(input). Output “Prime” if the number is prime, “Not Prime” otherwise.
Use a while loop to print the sequence 1, -2, 3, -4, 5, -6, 7, -8
Use a while loop to calculate pi using the Liebniz formula pi/4 = 1 – 1/3 + 1/5 – 1/7 + 1/9 – … How many iterations do you need to get 3.141?

2 – Selection Answers

1) Prompt the user as follows: “What’s the capital of France?” Output “Correct” if they enter “Paris”, output “Incorrect” otherwise

Scanner scan = new Scanner(System.in);
System.out.println("What's the capital of France?");
String ans = scan.nextLine();
if(ans.equalsIgnoreCase("Paris"))
{
    System.out.println("Correct");
}
else
{
    System.out.println("Incorrect");
}

2) Prompt the user as follows: “Name a month that starts with the letter A”: Output “Correct” if they enter “April” or “August”, output “Incorrect” otherwise

Scanner scan = new Scanner(System.in);
System.out.println("Name a month that starts with the letter A");
String ans = scan.nextLine();
if(ans.equalsIgnoreCase("April")||ans.equalsIgnoreCase("August"))
{
    System.out.println("Correct");
}
else
{
    System.out.println("Incorrect");
}

3) Prompt the user as follows: “Name a Beatle”. Output “Correct” if they enter “John”, “Paul”, “George” or “Ringo”, output “Incorrect” otherwise

Scanner scan = new Scanner(System.in);
System.out.println("Name a Beatle");
String ans = scan.nextLine();
if(ans.matches("John|Paul|George|Ringo"))
{
    System.out.println("Correct");
}
else
{
    System.out.println("Incorrect");
}

4) An online whisky shop charges for shipping as follows: One bottle, £5.99; two to five bottles, £7; more than five bottles, free. Prompt the user to enter the number of bottles bought and output the shipping cost.

Scanner scan = new Scanner(System.in);
System.out.println("Number bottles purchased:");
int number = scan.nextInt();
if(number == 1)
{
    System.out.println("Shipping £5.99");
}
else if (number <=5)
{
    System.out.println("Shipping £7");
}
else
{
    System.out.println("Shipping Free");
}

5) An online bookshop charges shipping as follows: Orders less than £10, £2.99; orders £10 and over, free; add on £2.50 for all orders if next day delivery is selected. Prompt the user to enter the cost of the order, and then prompt for next day delivery. Output the shipping cost.

Scanner scan = new Scanner(System.in);
System.out.println("Next Day Delivery (y/n)?");
String del = scan.nextLine();
System.out.println("Input order Cost:");
double cost = scan.nextDouble();
double shipping = 0;
shipping = cost < 10 ? 2.99 : 0;
if(del.equals("y"))
{
    shipping += 2.50;
}
System.out.println("Cost of shipping: £" + shipping);

6) Prompt the user to enter a number. Output if the number is odd or even.

Scanner scan = new Scanner(System.in);
System.out.println("Input Number:");
int number = scan.nextInt();
if(number % 2 == 0)
{
    System.out.println("even");
}
else
{
    System.out.println("odd");
}

7) Prompt the user to enter a number. Output Fizz if the number is divisible by 3, otherwise just output the number

Scanner scan = new Scanner(System.in);
System.out.println("Input Number:");
int number = scan.nextInt();
if(number % 3 == 0)
{
    System.out.println("Fizz");
}
else
{
    System.out.println(number);
}

8) Extend yesterday’s problem so that the computer will output Fizz if the number is divisible by 3, output Buzz if the number is divisible by 5 and otherwise just output the number.

Scanner scan = new Scanner(System.in);
System.out.println("Input Number:");
int number = scan.nextInt();
if(number % 3 == 0)
{
    System.out.println("Fizz");
}
else if(number % 5 == 0)
{
    System.out.println("Buzz");
}
else
{
    System.out.println(number);
}

9) Now extend yesterday’s problem further so that the computer will output Fizz if the number is divisible by 3, output Buzz if the number is divisible by 5, output Fizz Buzz if the number is divisible by both 5 and 3 and otherwise just output the number.

Scanner scan = new Scanner(System.in);
System.out.println("Input Number:");
int number = scan.nextInt();
if(number % 3 == 0 && number % 5 ==0)
{
    System.out.println("Fizz Buzz");
}
else if(number % 3 == 0)
{
    System.out.println("Fizz");
}
else if(number % 5 == 0)
{
    System.out.println("Buzz");
}
else
{
    System.out.println(number);
}

2 – Selection (Level 2)

1 Sample Code

1.1 Simple Selection

System.out.println("Enter your surname");
Scanner scan = new Scanner(System.in);
String surname = scan.next();
System.out.println("Are you M or F?");
String sex = scan.next();
if(sex.equals("M"))
{
    System.out.println("Hello Mr " + surname);
}
else
{
    System.out.println("Hello Ms " + surname);
}

1.2 Operators

public class  div37
{
    public static void main (String args [])
    {
        int x = 21;
        if (x%3 == 0 & x%7 == 0)
            {
                System.out.println("Number divisible by 3 and 7");
            }
    }
}

2 Exercises

Prompt the user as follows: “What’s the capital of France?” Output “Correct” if they enter “Paris”, output “Incorrect” otherwise
Prompt the user as follows: “Name a month that starts with the letter A”: Output “Correct” if they enter “April” or “August”, output “Incorrect” otherwise
Prompt the user as follows: “Name a Beatle”. Output “Correct” if they enter “John”, “Paul”, “George” or “Ringo”, output “Incorrect” otherwise
An online whisky shop charges for shipping as follows: One bottle, £5.99; two to five bottles, £7; more than five bottles, free. Prompt the user to enter the number of bottles bought and output the shipping cost.
An online bookshop charges shipping as follows: Orders less than £10, £2.99; orders £10 and over, free; add on £2.50 for all orders if next day delivery is selected. Prompt the user to enter the cost of the order, and then prompt for next day delivery. Output the shipping cost.
Prompt the user to enter a number. Output if the number is odd or even.
Prompt the user to enter a number. Output Fizz if the number is divisible by 3, otherwise just output the number
Extend yesterday’s problem so that the computer will output Fizz if the number is divisible by 3, output Buzz if the number is divisible by 5 and otherwise just output the number.
Now extend yesterday’s problem further so that the computer will output Fizz if the number is divisible by 3, output Buzz if the number is divisible by 5, output Fizz Buzz if the number is divisible by both 5 and 3 and otherwise just output the number.

1 – Input and Output Answers

1) Use the \t escape character to print out a noughts and crosses grid, as shown below in fig. 1

System.out.println("|\to\t|\t \t|\tx\t|");
System.out.println("|\t \t|\tx\t|\to\t|");
System.out.println("|\to\t|\tx\t|\to\t|");

2) Prompt the user to enter their (name). Print out “Hello” (name) “I hope you’re well”

Scanner scan = new Scanner(System.in);
System.out.println("Enter your name");
String name = scan.nextLine();
System.out.println("Hello " + name + ". I hope you're well.");

3) Use Math.sqrt() to print out the square root of 20

System.out.println(Math.sqrt(20));

4) Use Math.sqrt() to print out the square root of 20 to 2 decimal places

double root = Math.round(Math.sqrt(20)*100)/100d;
System.out.println(root);

5) Use Math.random() to print out a random integer between 5 and 10

System.out.println((int)(Math.random()*5)+5);

6) Use Math.pow() to print out 2 to the power of 8

System.out.println(Math.pow(2,8));

7) Prompt the user to enter a (number). Print out “The square root of ” (number) ” is ” (answer)

Scanner scan = new Scanner(System.in);
System.out.println("Emter a number");
double num = scan.nextDouble();
System.out.println("The square root of " + num + " is " + Math.sqrt(num));

Scanner scan = new Scanner(System.in);
System.out.println("Emter a number");
double num = scan.nextDouble();
System.out.format("The square root of %f is %f%n", num, Math.sqrt(num));

8) Prompt the user to enter two numbers. Print out the average of those numbers.

Scanner scan = new Scanner(System.in);
System.out.println("Emter a number");
double num1 = scan.nextDouble();
System.out.println("Enter another number");
double num2 = scan.nextDouble();
double average = (num1 + num2)/2;
System.out.println("The average of " + num1 + " and " + num2 + " is " + average);

9) To work out your BMI, divide your weight in kilograms by your height in metres squared. In other words BMI = w / h*h. Write a program that prompts the user to input their weight and height, and then outputs their BMI.

Scanner scan = new Scanner(System.in);
System.out.println("Emter your weight in kilograms");
double weight = scan.nextDouble();
System.out.println("Enter your height in meters");
double height = scan.nextDouble();
double BMI = weight/(height*height);
System.out.println("Your BMI is " + BMI);

1 Input and Output (Level 1)

Sample Code

Escape Characters

Escape Sequence	Character
\n	newline
\t	tab
\b	backspace
\”	double quote
\’	single quote
\\	backslash
\uDDDD	Unicode character

public class uni
{
    public static void main (String args [])
    {
        System.out.println("\u0041");
    }
}

Simple Scanner

import java.util.Scanner;
public class Simpscan
{
    public static void main (String args [])
    {
        System.out.println("Enter your name");
        Scanner scan = new Scanner(System.in);
        String s = scan.next();
        System.out.println("Hello " + s);
    }
}

System.out.format

double pi = 3.1415;
System.out.format("Pi is %f to 4 d.p.%n", pi);

#+RESULTS

Pi is 3.141500 to 4 d.p.

Exercise

Use the \t escape character to print out a noughts and crosses grid, as shown below in fig. 1
Prompt the user to enter their (name). Print out “Hello” (name) “I hope you’re well”
Use Math.sqrt() to print out the square root of 20
Use Math.sqrt() to print out the square root of 20 to 2 decimal places
Use Math.random() to print out a random integer between 5 and 10
Use Math.pow() to print out 2 to the power of 8
Prompt the user to enter a (number). Print out “The square root of ” (number) ” is ” (answer)
Prompt the user to enter two numbers. Print out the average of those numbers.
To work out your BMI, divide your weight in kilograms by your height in metres squared. In other words BMI = w / h*h. Write a program that prompts the user to input their weight and height, and then outputs their BMI.

Table 1: fig. 1
o		x
	x	o
o	x	o