Control structures (if, for) in Flask - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the {% if %} statement in Flask templates?

The {% if %} statement is used to conditionally display parts of the HTML based on a condition. It helps show or hide content dynamically.

beginner

How do you loop over a list in a Flask template?

You use the {% for item in list %} statement to repeat HTML for each item in the list. It helps display multiple items like a list or table rows.

beginner

What happens if the {% if %} condition is false in a Flask template?

The HTML inside the {% if %} block is skipped and not shown. You can use {% else %} to show alternative content.

intermediate

Can you nest {% for %} loops inside each other in Flask templates?

Yes, you can nest {% for %} loops to handle complex data like lists of lists. Just make sure to use different variable names to avoid confusion.

beginner

What is the syntax to end a control structure like {% if %} or {% for %} in Flask templates?

You close control structures with {% endif %} for if and {% endfor %} for for loops.

Which tag starts a conditional block in a Flask template?

A {% if %}

B {% for %}

C {{ if }}

D <if>

The {% if %} tag starts a conditional block in Flask templates.

How do you end a for loop in a Flask template?

A {% endfor %}

B {% endloop %}

C {% endforeach %}

D {% end %}

You end a for loop with {% endfor %} in Flask templates.

What will happen if the condition in {% if %} is false and there is no {% else %}?

A The whole template stops rendering

B An error occurs

C The if block content is shown anyway

D Nothing inside the if block is shown

If the condition is false and no else block exists, the content inside the if block is skipped.

Which of these is a correct way to loop over a list named 'items' in Flask template?

A {% loop item in items %}

B {% for item in items %}

C {{ for item in items }}

D <for each='items'>

The correct syntax is {% for item in items %}.

Can you use an if statement inside a for loop in Flask templates?

A No, only one control structure per template

B Only if you use special syntax

C Yes, nesting control structures is allowed

D Only outside the loop

You can nest if statements inside for loops to control what is shown for each item.

Explain how to use {% if %} and {% for %} in a Flask template to show a list only if it has items.

Think about showing content only when there is something to show.

Describe how nesting a for loop inside an if statement works in Flask templates.

Imagine checking a condition before listing items.