First PHP program (Hello World) - Step-by-Step Execution

Concept Flow - First PHP program (Hello World)

Start PHP script

↓

Execute echo statement

↓

Output: Hello World

↓

End script

The PHP script starts, runs the echo command to print 'Hello World', then ends.

Execution Sample

PHP

<?php
echo "Hello World";

This code prints the text 'Hello World' to the screen.

Execution Table

Step	Action	Evaluation	Output
1	Start PHP script	N/A
2	Execute echo statement	echo "Hello World";	Hello World
3	End script	N/A

💡 Script ends after printing 'Hello World'.

Variable Tracker

Variable	Start	After Step 2	Final
No variables	N/A	N/A	N/A

Key Moments - 2 Insights

Why do we use <?php and ?> tags?

These tags tell the server where PHP code starts and ends, as shown in step 1 and step 3 of the execution_table.

What does the echo statement do?

Echo prints the text to the screen immediately, as seen in step 2 where 'Hello World' is output.

Visual Quiz - 3 Questions

Look at the execution table, what is printed at step 2?

A No output

B echo "Hello World";

C Hello World

D PHP code

💡 Hint

Check the Output column in row for step 2 in the execution_table.

At which step does the PHP script end?

A Step 3

B Step 2

C Step 1

D After Step 2

💡 Hint

Look at the Action column in the execution_table for the step labeled 'End script'.

If we remove the closing ?> tag, what happens?

A The script will not run

B The script still runs and prints 'Hello World'

C Syntax error occurs

D Output will be empty

💡 Hint

PHP allows omitting the closing tag at the end of a file without error.

Concept Snapshot

<?php ... ?> tags mark PHP code start and end.
echo prints text to the screen.
This program outputs: Hello World
No variables needed.
Script runs top to bottom.

Full Transcript

This PHP program starts with the <?php tag and ends with ?>. Inside, it uses echo to print the text 'Hello World' to the screen. The execution starts by reading the PHP code, then runs the echo statement which outputs the text immediately. After that, the script ends. There are no variables used in this simple program. The closing ?> tag is optional if the PHP code is at the end of the file. This is the simplest way to write a PHP program that shows output.