Need help with Perl, using perl 5 Exercise A7 The following statements set the v
ID: 3600768 • Letter: N
Question
Need help with Perl, using perl 5
Exercise A7
The following statements set the values:
$x = 3;
$y = 0;
$z = -4;
Then, which of the following expressions evaluate to true, and which evaluate to false?
!( $x < $y ) = True
!( $x >= $y ) False
!( (4 + 5 * $y) >= $z -2 ) && ( $z - 2 )
!($x) && !($y) || !($z)
Exercise A8
Code a single statement, which uses the && operator, and produces the same results as this code:
if ( $x < 10 )
{
$x++;
}
Exercise A9
Code a single statement, which uses the || operator, and produces the same results as this code:
unless ( $x < 10 )
{
$x++;
}
Explanation / Answer
Exercise A7
The following statements set the values:
$x = 3;
$y = 0;
$z = -4;
Then, which of the following expressions evaluate to true, and which evaluate to false?
a) !( $x < $y ) = True
Answer: Evaluates True
Program:
$x = 3;
$y = 0;
$z = -4;
if (!( $x < $y ))
{
print "True";
}
else
{
print "False";
}
Output: True
b) !( $x >= $y ) False
Answer: Evaluates True
Program:
$x = 3;
$y = 0;
$z = -4;
if (!( $x >= $y ))
{
print "False";
}
else
{
print "True";
}
Output: True
c) !( (4 + 5 * $y) >= $z -2 ) && ( $z - 2 )
Answer: Evaluates False
Program:
$x = 3;
$y = 0;
$z = -4;
if (!( (4 + 5 * $y) >= $z -2 ) && ( $z - 2 ))
{
print "True";
}
else
{
print "False";
}
Output:False
d) !($x) && !($y) || !($z)
Answer: Evaluates False
Program:
$x = 3;
$y = 0;
$z = -4;
if (!($x) && !($y) || !($z))
{
print "True";
}
else
{
print "False";
}
Output: False
Exercise A8 :
$x = 3;
if ( $x < 10 && $x > 2 )
{
$x++;
}
print $x;
Output: 4
Exercise A9:
$x = 3;
unless ( $x < 10 || $x >10)
{
$x++;
}
print $x;
Output: 3