Saturday, 6 August 2016

PHP Introduction - Lecture #4

Operators, Concatenation, Comments

Hello All... welcome every one. I'm going to start PHP lectures for Very Beginners, who wants to learn PHP from very beginning. No matter if you do not have any basic programming concept. If you follow my tutorials I hope you will surely get some how good knowledge of PHP.
Today our Topic is

OPERATORS

There are four types of operators
1-    Arithmetic Operator
a.     Addition (+)
b.     Subtraction (-)
c.      Multiplication (*)
d.     Division (/)
e.     Modulus (%)
2-    Assignment Operator
a.     =
b.     +=
c.      -=
d.     *=
e.     /=
f.       .=
g.     %=
3-    Comparison Operator
a.     is equal to                 (==)
b.     is not equal to         (!=)
c.      is not equal to         (<>)
d.     is greater than         (>)
e.     is less than                (<)
f.       is greater than or equal to           (>=)
g.     is less than or equal to                  (<=)
4-    Logical Operator
a.     AND   ( && )
b.     OR      ( || )
c.      NOT    ( ! )

Increment/decrement Operators

Increment operator ++
            Increment operator adds +1 to the given value
Decrement operator –
            Decrement operator subtracts the -1 from the given value.
Example:
<?php
            $a = 10;
            $a++;
            echo $a;
// the result will be 11. Increment operator adds 1 to the variable.
            $b = 5;
            $b--;
            echo $b;
// the result will be 4. Decrement operator subtracts -1 from the variable;
?>

Concatenation

Concatination means to combine something. Here in almost each programming language we use concatenation to combine two parts or two statements as to result as a single statement. Here is an example:
<?php
            $var1 = “hello this is an example”;
            $var2 = “of concatenation”;
            echo $var1 . $var2;
// this will result as `hello this is an exampleof concatenation`
?>
to give space between exampleof words just apply space at the end of first variable or from the first of second variable, within quotations.

Comments

Comments are used by developers in order to know about his code that for what purpose this code is about. Comments are also very useful for the end users if he/she will see the comments besides the code he/she will surely know that what you have written in your code, and what’s logic developer has applied in it. Comments will not affect your code even if you write between your code just place double forward slash `//` before you start writing comment or another way is to write this `/* */` between these you must write comment whatever you want to write in your comment.
// comment is known as Single line Comment
/*   is known as multiline comment.
Whatever we will write between this will not affect our */
It’s very good approach to use comments for every important part of code.

Thanks Guys. Any thing missing or any question from this topic you can comment below, I will be trying to solve and answer your question.
Our Next topic will be `Conditions`.

Good Luck J

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