Some practice problems for Quiz 2



what is the output ?


$sum=0;
$a=1;
while($a<10)
{
    $b=2;
    while( $b<7)
    {
        $sum=$sum+$a=$b;
        print "A is $a  B is $b  Sum is $sum\n";
        $b=$b+2;
    }
    $a=$a+4;
}

print "A is $a  B is $b  Sum is $sum\n";

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what is the output ?

for( $a=10; $a>=1;$a--)
{
    for($b=1;$b<=10;$b++)
    {
        if ( $b < $a )
        {
            print ' ';
         }
        else
        {
            print '*';
        }
        print '\n';
    }
}

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what is the output?

use strict;
my @data;
my $i;

$data[0]=3;
$data[1]=0;
$data[2]=4;
$data[3]=1;
$data[4]=2;

for($i = 0 ; $i < =$#data ; $i++)
{
        print "  $data[$i]    $data[$data[$i]]  \n";                #no, this isn't a misprint
}

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Fibonacci Numbers!!!!
Fibonacci numbers are defined as follows:
    - the first Fibonacci number is 1. That is, fib(1)=1
    - the second Fibonacci number is 1. That is, fib(2)=1
    - for any n greater than 1, fib(n)=fib(n-1)+fib(n-2).  
So fib(3)= fib(2)+fib(1) = 1 + 1 = 2
fib(4)=fib(3)+fib(2) = 2 + 1 = 3
fib(5)=fib(4)+fib(3) = 3 + 2 = 5

Easy program: use an array to find and print out the first 20 Fibonacci numbers
Harder Program : without using an array, print out the first 20 Fibonacci numbers
----------------------------------------------------------
Simple practice problem:

- declare an array called @numbers
- fill up the first 20 slots of @numbers with the sequence 0,5,10,15,20,........
- print out this array in reverse

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Do you understand the perl last and next statements ?
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Write a complete perl loop that prompts (asks!!) the user to enter an even number. If the number entered is not even,
a warning message is displayed and the user must again enter a number. Once an even number is entered, the program
should respond "Thank You".