PHP

Basic structures: (PHP tutorials: Part-3)

Written by Saiful Islam

Previous chapter: Part-1

Basic structure:

  1. At the beginning of PHP coding language we have to write “ <?php ” this code to announce that we are going to prepare a php document. To end the whole PHP code we have to just write “ ?> “ this simple code.

So, the document turns to the following phase:

  1. To make a PHP file we must have to save the PHP code through keeping the ” .php ” extension at the end of the file name. Example: tech-info24.php .

Even if we rename a file by keeping “.php” at the last then the file will become a php file.

Showing an output

To show any output we have to use the “echo” code. It is used to show both text and the value of variables.

No. Input Output
  1.      
The structure for showing any text is :
 
This is a sample text
     2. The structure for showing any variables is :
10

 If we want to show both variables and text at a time:

We have to use the dot ( . ) sign to represent both the text and the value of x.

 Input  Output
 The value of x is 10.

Providing comments:

Comments on PHP are used to simplify the PHP code to the checker so that he/she can easily identify the whole code within a short time.

Two type of structures are available for that like following:

Usage of Variables

What is variable?

Variables can be defined as the carrier of the information or storehouse of values. In different programming languages(like PHP, C programming, Java, Python, SQL, etc.) variables are used to pass values through a program.

Variables in PHP:

To input a value on the program you need to use the “ $ “ sign just before the variable name. Then we can input any value using those variables. Through those variables we can perform mathematical calculations.

Examples:

No. Input Output
1. 30
2. 200

Description:

In example-1, b and x are variables. The value of a and b is 10 and 20. The summation of a and b is 30. If we want to use this number for any purpose then we need to store that in a variable. So, here I have considered the “x” as the carrier of “30”. That means 30 have been stored in x. To show the value of x, I have used the “echo” to present the output.

In example-2, everything is same but there is a multiply sign(*) instead of the summation sign(+). So, the output will be different(200). So, different number will be stored on the variable “x”.

Note:

The star sign ( * ) is used as the multiply sign.

About the author

Saiful Islam

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