Day 2 - Variables - Become PHP Expert in 30 days

[sherlyk]

http://php.flashwebhost.com/sherly/add.php

<?php

$M = 20;
$N = 50;
echo $M + $N;

[admin]

http://php.flashwebhost.com/sherly/add.php

<?php

$M = 20;
$N = 50;
echo $M + $N;

It is always better to use descriptive name for variables, so you what what is stored in a variable. For example, to store mark, we use variable $mark

It is ok, but better use descriptive names for variables. One letter variable names can be confusing in most cases.

[annie]

I got an error while adding break in http://php.flashwebhost.com/annie/company.php

Parse error:  syntax error, unexpected '>' in /home/fwhphp/public_html/annie/company.php on line 3 

 <?php
$companyname = 'Relience';
echo $companyname <br> ; 
$companyname = 'Whirpool'; 
echo $companyname ;

[sherlyk]

I got an error http://php.flashwebhost.com/sherly/name.php

Parse error:  syntax error, unexpected '' ;' (T_ENCAPSED_AND_WHITESPACE), expecting ',' or ';' in /home/fwhphp/public_html/sherly/name.php on line 7

<?php
$my_string = 'Hi Meera. My anme is Neena';
$my_number = 8;
$my_letter = N;
echo $my_string;
echo $my_number;
echo $my_letter' ;

[admin]

I got an error http://php.flashwebhost.com/sherly/name.php

<?php
$my_string = 'Hi Meera. My anme is Neena';
$my_number = 8;
$my_letter = N;
echo $my_string;
echo $my_number;
echo $my_letter' ;

Good, more friendly code with some string.

<?php

$my_string = 'Hi Meera. My anme is Neena';
$my_number = 8;
$my_letter = N;

echo '<h1>About Me</h1>';
echo $my_string;
echo '<br>';
echo 'My number is ' . $my_number;
echo '<br>';
echo 'My Name start with ' . $my_letter' ;
echo '<br>';

[admin]

I got an error while adding break in http://php.flashwebhost.com/annie/company.php

Parse error:  syntax error, unexpected '>' in /home/fwhphp/public_html/annie/company.php on line 3 

 <?php
$companyname = 'Relience';
echo $companyname <br> ; 
$companyname = 'Whirpool'; 
echo $companyname ;

Problem is on line number 3.

echo $companyname <br> ;

To fix, replace that line with

echo $companyname .  '<br>' ;

$companyname is a variable. We use DOT to join it with string <br>. String should start with a quote, end with a quote.

As for variable name, proper naming convention is $companyName, because it is two words, and easy to read.


Fixed code

<?php

$companyName = 'Relience';

echo $companyname .  '<br>'; 

// here we store another text to same variable $companyName
$companyName = 'Whirpool'; 

echo $companyname ;

[annie]

http://php.flashwebhost.com/annie/day_2_variables_3.php

 
<?php
$name = 'George';
$Rank = 1;
$Mark = 800;
$School = 'Raja Giri Public School';
echo $name . ' from ' . $School . ' got Rank ' . $Rank . ' He have ' . $Mark . 'Marks';

[sherlyk]

I didn't get the correct answer. http://php.flashwebhost.com/sherly/variable.php

<?php

$variable12 = $variable7 + $variable5;
echo $variable7;
echo " + ";
echo $variable5;
echo " = ";
echo $variable12;

[sherlyk]

http://php.flashwebhost.com/sherly/age.php

<?php

$name = 'Joseph';
$yearBorn = 1975;
$currentYear = 2014;
$age = $currentYear - $yearBorn;

print ("$name is $age years old. ")

[admin]

http://php.flashwebhost.com/sherly/age.php

<?php

$name = 'Joseph';
$yearBorn = 1975;
$currentYear = 2014;
$age = $currentYear - $yearBorn;

print ("$name is $age years old. ")

Semicolon at end of print statement missing.

print function same as echo, but use echo, forget print. echo is more popular, also there are more ways to print, some complicated, but is not required for most programming project.

print ("$name is $age years old. ")

Proper usage

echo $name . ' is ' .  $age . ' years old. ';

Or

echo "$name  is  $age years old. ";

Advantage of using single quote is PHP know it is just string, so it will be faster. If using double quote, PHP compilter need to look for variable inside the string and convert it to its value, that need more processing time (not much, still do that way as a convention whenever possible).