these operators are discussed thoroughly in our perl operators lesson

8/9/2019 These Operators Are Discussed Thoroughly in Our PERL Operators Lesson.

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Conditional statements may involve logical operators and usually test equality orcompare one value to another. Here's a look at some common conditional statements.Remember that the code to be executed will only execute if the condition in parenthesesis met.ifs.pl:

#!/usr/bin/perl

# HTTP HEADERprint "content-type: text/html \n\n";

# SOME VARIABLES$x = 7;$y = 7;

# TESTING...ONE, TWO...TESTING

if ($x == 7) {print '$x is equal to 7!';print "
";

}if (($x == 7) || ($y == 7)) {

print '$x or $y is equal to 7!';print "
";

}if (($x == 7) && ($y == 7)) {

print '$x and $y are equal to 7!';print "
";


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}

if.pl:$x is equal to 7!$x or $y is equal to 7!


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$x and $y are equal to 7!

These operators are discussed thoroughly in our PERL Operators lesson.PERL - If Else

The else statement is a perfect compliment to an if statement. The idea behind them isthat if the conditional statement is not met then do this. In hypothetical, plain english, "Ifthis is true do this, if not do this."ifelse.pl:


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#!/usr/bin/perl

# HTTP HEADERprint "content-type: text/html \n\n";


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# SOME VARIABLES$name = "Sarah";

$x = 5;

all television

stationsbroadcasting

workersarriving in


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Indonesiafollowing themovementsinvolved Teruadi want to seehear thetelevision tohear music


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everywherewant out of theroom to the

bedroom tosleep wants totake a showergo whereverour leaders


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commandertelevision

broadcasters areeager to

participatepemimpinnnyarobert adhiKusuma's son


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# IF/ELSE STATEMENTSif ($x > 10) {

print "$x is greater than 10!";} else {

print "$x is not greater than 10!";}print "
";

# STRINGS ARE A LITTLE DIFFERENTif ($name eq "Sarah") {

print "Hello, $name!";

} else {print "You are not $name!";

}

PERL - Elsif Statements

Elsif statements test another conditional statement before executing code. This waymultiple conditions can be tested before the script continues.


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elsif.pl:

#!/usr/bin/perl

# HTTP HEADER

print "content-type: text/html \n\n";

# SOME VARIABLES

$x = 5;

# PLAY THE GUESSING GAME

if ($x == 6) {print "X must be 6.";

}elsif ($x == 4) {

print "X must be 4.";}elsif ($x == 5) {

print "X must be 5!";


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}

We could take this example a step further, adding an else statement at the bottom. Thiswould serve as a catch all if none of the conditions were met.

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More Tutorials!Microsoft Office Tutorials Artist Tutorials While loops continually iterate as long as theconditional statement remains true. It is very easy to write a conditional statement thatwill run forever especially at the beginner level of coding. On a more positive note, whileloops are probably the easiest to understand. The syntax is while (coditional statement){ execute code; }.Advertise on Tizag.comwhilecounter.pl:

#!/usr/bin/perl



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# SET A VARIABLE$count = 0;

# RUN A WHILE LOOPwhile ($count


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1 all televisionstations

broadcastingworkersarriving inIndonesiafollowing themovements


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involved Teruadi want to seehear thetelevision tohear musiceverywherewant out of theroom to the


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bedroom tosleep wants totake a showergo whereverour leaderscommandertelevision

broadcasters are


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eager toparticipatepemimpinnnyarobert adhiKusuma's son234567Finished Counting!PERL - Next, Last, and Redo

Outlined below are several interrupts that can be used to redo or even skip iterations of

code. These functions allow you to control the flow of your while loops.

NextPlace it inside your loop and it will stop the current iteration and go on to the next one.ContinueExecuted after each loop iteration and before the conditional statement is evaluated. Agood place to increment counters.Last


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Last stops the looping immediately (like break)RedoRedo will execute the same iteration over again.

flowcontrol.pl:

#!/usr/bin/perl


# SET A VARIABLE

$count = 0;while ($count


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# PRINT THE COUNTER

print $count."
";

}continue {

$count++;};

print "Loop Finished!";

flowcontrol.pl:0

123Skip Four!567Finished Counting!


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Above, we skip the fourth iteration by incrementing the variable again. In the example wealso print a line, "Skip Four!" just to make things easier to follow.PERL - While Array Loop

Here we are just showing a method of looping through an array using a while loop. Weuse three variables to do this including: the array, a counter, and an index number so thateach time the while loop iterates we also loop through each index of the array.whilearrayloop.pl:

#!/usr/bin/perl


# SET UP AN HTML TABLEprint "";

# DEFINE AN ARRAY@names = qw(Steve Bill Connor Bradley);

# COUNTER - COUNTS EACH ROW$count = 1;

# COUNTS EACH ELEMENT OF THE ARRAY$n = 0;

# USE THE SCALAR FORM OF ARRAYwhile ($names[$n]) {

print "$count$names[$n]";$n++;$count++;

}print "";

while.pl:1 Steve2 Bill3 Connor 4 Bradley

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Web ReferenceHTML Reference CSS Reference CSS Examples PHP Examples Help Tizag GrowLink to TizagNew - Tizag.com Forums!Recent Forum Topics:- table border colors- Wanna Make Money, Its Very Simple... Here's A Way!!- Getting this code to work

- What do you think/and little problem.

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these operators are discussed thoroughly in our perl operators lesson

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