Example 2: Personal Data

Concatenating multiple variables in PHP

Download file datos_personales

🎯 Live Demo

Code output:

Hi, my name is Jorge, I am 21 years old and I am from Talavera de La Reina

Personalize your data!

📖 Code Explanation

Complete PHP Code

<?php
$nombre = "Jorge";
$edad = "21";
$ciudad = "Talavera de La Reina";
echo "Hola, me llamo $nombre, tengo $edad años y soy de $ciudad";
?>

📝 Lines 1-3: Variable declaration

$nombre = "Jorge";
$edad = "21";
$ciudad = "Talavera de La Reina";

What does it do? Creates three different variables with personal data.

Why is it done this way? Each variable stores a specific type of information, making the code more organized and easier to maintain.

💡 Concept: Variable naming

It's good practice to use descriptive names for variables. In PHP we use snake_case (all lowercase with underscores).

📝 Line 4: Automatic concatenation

echo "Hola, me llamo $nombre, tengo $edad años y soy de $ciudad";

What does it do? Combines fixed text with variables into a single message.

Why is it done this way? PHP automatically replaces variables inside double quotes, making concatenation more readable.

💡 Concept: Concatenation vs Interpolation

Interpolation: Variables inside double quotes (more readable)
Concatenation: Join strings with . (more control)

📝 Alternative with concatenation

echo "Hola, me llamo " . $nombre . ", tengo " . $edad . " años y soy de " . $ciudad;

What does it do? The same result but using the concatenation operator .

When to use it? When you need more control or when using single quotes.

💡 Concept: Concatenation operator

The . dot joins strings. Useful when working with single quotes or needing complex formatting.

🎯 Key Concepts Learned

Multiple Variables

  • You can declare as many variables as you need
  • Each variable must have a unique name
  • Organizes related information
  • Facilitates data reuse

Variable Interpolation

  • Only works in double quotes
  • More readable than concatenation
  • PHP replaces automatically
  • Ideal for simple texts

Data Types

  • String: Text in quotes
  • Integer: Whole numbers
  • Float: Decimal numbers
  • PHP converts automatically

💪 Practical Exercise

Extend the code

Practice these changes to improve your skills:

  1. Add a variable $pais and include it in the message
  2. Change the message to use single quotes with concatenation
  3. Create a more formal message: "Mi nombre es [nombre], tengo [edad] años y resido en [ciudad]"
  4. Experiment mixing numbers as text and as integers

Solution 1: Add country

<?php
$nombre = "Jorge";
$edad = "21";
$ciudad = "Talavera";
$pais = "España";
echo "Hola, me llamo $nombre, tengo $edad años y soy de $ciudad, $pais";
?>

Solution 2: Single quotes

<?php
$nombre = "Jorge";
$edad = "21";
$ciudad = "Talavera";
echo 'Hola, me llamo ' . $nombre . ', tengo ' . $edad . ' años y soy de ' . $ciudad;
?>

Solution 3: Formal message

<?php
$nombre = "Jorge";
$edad = 21;
$ciudad = "Talavera de La Reina";
echo "Mi nombre es $nombre, tengo $edad años y resido en $ciudad";
?>

Solution 4: Data types

<?php
$nombre = "Jorge";
$edad = 21;  // Como integer
$ciudad = "Talavera";
echo "Hola, me llamo $nombre, tengo " . $edad . " años y soy de $ciudad";
?>

⚖️ Comparison: Interpolation vs Concatenation

Interpolation (Double Quotes)

echo "Hola $nombre";

✅ Advantages:

  • More readable
  • Shorter code
  • Easier to write

❌ Disadvantages:

  • Only in double quotes
  • Less control
  • Can be confused with arrays

Concatenation (Operator .)

echo 'Hola ' . $nombre;

✅ Advantages:

  • Works with any type of quotes
  • More control over formatting
  • Better for complex code

❌ Disadvantages:

  • Longer code
  • More error-prone
  • Less readable