Twig If/Else - PHP

Twig is a templating engine for PHP that allows developers to create dynamic templates using a syntax that is easy to read and write. One of the most useful features of Twig is the if/else statement.

Syntax

The if/else statement in Twig is very similar to the if/else statement in PHP. It allows you to execute code based on a certain condition.

The basic syntax for the if/else statement in Twig is as follows:

{% if condition %}
    {# Do something if the condition is true #}
{% else %}
    {# Do something else if the condition is false #}
{% endif %}

Here, condition is any expression that evaluates to either true or false.

Examples

Let's take a look at some examples of how the if/else statement is used in Twig:

Example 1: Display a message if a variable is true

{% if is_authenticated %}
    Welcome back, {{ user.name }}!
{% endif %}

Here, is_authenticated is a variable that contains either true or false. If it is true, the message "Welcome back, !" will be displayed, where <username> is the value of the user.name variable.

Example 2: Display a different message if a variable is false

{% if not is_authenticated %}
    Please log in to continue.
{% endif %}

Here, the not keyword is used to negate the value of is_authenticated. If it is false, the message "Please log in to continue." will be displayed.

Example 3: Display different messages depending on the value of a variable

{% if num_comments == 0 %}
    Be the first to leave a comment!
{% elseif num_comments == 1 %}
    There is one comment.
{% else %}
    There are {{ num_comments }} comments.
{% endif %}

Here, num_comments is a variable that contains the number of comments on a blog post. Depending on its value, a different message will be displayed.

If num_comments is 0, the message "Be the first to leave a comment!" will be displayed.

If num_comments is 1, the message "There is one comment." will be displayed.

If num_comments is any other value, the message "There are comments." will be displayed, where <number> is the value of the num_comments variable.

Conclusion

The if/else statement is a powerful tool in Twig that allows you to create dynamic templates based on conditions. By using the examples provided above, you can start incorporating this feature into your own code and create more dynamic and interactive web pages.