Function execution model in Azure - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the trigger type for an Azure Function.

Azure

trigger: [1]

Drag options to blanks, or click blank then click option'

AhttpTrigger

BblobTrigger

CqueueTrigger

DtimerTrigger

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a trigger that starts on storage events instead of HTTP requests.

Using a timer trigger when expecting an HTTP request.

The httpTrigger is used to start an Azure Function when an HTTP request is received.

2fill in blank

medium

Complete the code to define the runtime version for an Azure Function app.

Azure

runtimeVersion: [1]

Drag options to blanks, or click blank then click option'

A~3

B~4

C~2

D~1

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting an older runtime version that lacks current features.

Confusing the runtime version with the language version.

The ~4 version is the latest major runtime version for Azure Functions, supporting the newest features.

3fill in blank

hard

Fix the error in the function.json binding direction property.

Azure

"direction": "[1]"

Drag options to blanks, or click blank then click option'

Aout

Binput

Coutput

Din

Attempts:

3 left

💡 Hint

Common Mistakes

Using full words like 'input' or 'output' instead of 'in' or 'out'.

Mixing up input and output directions.

The correct value for the binding direction property is in or out. Here, in is the valid choice.

4fill in blank

hard

Fill both blanks to configure an Azure Function with a timer trigger and a schedule.

Azure

{
  "bindings": [
    {
      "type": "[1]",
      "schedule": "[2]"
    }
  ]
}

Drag options to blanks, or click blank then click option'

AtimerTrigger

BhttpTrigger

C0 */5 * * * *

D0 0 * * * *

Attempts:

3 left

💡 Hint

Common Mistakes

Using httpTrigger with a schedule property.

Choosing a schedule that does not match the intended frequency.

The timerTrigger type is used for scheduled functions. The schedule 0 */5 * * * * runs the function every 5 minutes.

5fill in blank

hard

Fill all three blanks to define an Azure Function with an HTTP trigger, a route, and an authorization level.

Azure

{
  "bindings": [
    {
      "type": "[1]",
      "route": "[2]",
      "authLevel": "[3]"
    }
  ]
}

Drag options to blanks, or click blank then click option'

AhttpTrigger

Bapi/items

Cfunction

DtimerTrigger

Attempts:

3 left

💡 Hint

Common Mistakes

Using timerTrigger instead of httpTrigger.

Setting an invalid route format.

Confusing authLevel values.

The httpTrigger type defines an HTTP-triggered function. The route specifies the URL path, here api/items. The authLevel set to function requires a function key for access.

Practice

1. What triggers an Azure Function to run?

easy

A. Only when the server restarts

B. Manual start from the Azure portal only

C. An event like an HTTP request or timer

D. When a user logs into Azure

Solution

1. Step 1: Understand Azure Function triggers

   Azure Functions start running when an event happens, such as an HTTP request or a timer firing.

2. Step 2: Eliminate incorrect options

   Manual starts, server restarts, or user logins are not triggers for Azure Functions.

3. Final Answer:

   An event like an HTTP request or timer -> Option C

4. Quick Check:

   Azure Functions run on events = A [OK]

Hint: Azure Functions run on events, not manual or login actions [OK]

Common Mistakes:

• Thinking functions run only manually
• Confusing server restart with trigger
• Assuming user login triggers function

2. Which of the following is the correct way to define an HTTP trigger in an Azure Function's function.json file?

easy

A. {"bindings": [{"type": "httpTrigger", "direction": "in", "authLevel": "function", "methods": ["get"]}]}

B. {"bindings": [{"type": "timerTrigger", "direction": "out", "schedule": "0 */5 * * * *"}]}

C. {"bindings": [{"type": "queueTrigger", "direction": "in", "queueName": "myqueue"}]}

D. {"bindings": [{"type": "httpOutput", "direction": "in"}]}

Solution

1. Step 1: Identify HTTP trigger binding

   The correct binding for an HTTP trigger uses "type": "httpTrigger", "direction": "in", and specifies methods like "get".

2. Step 2: Check other options for errors

   {"bindings": [{"type": "timerTrigger", "direction": "out", "schedule": "0 */5 * * * *"}]} is a timer trigger with wrong direction; {"bindings": [{"type": "queueTrigger", "direction": "in", "queueName": "myqueue"}]} is a queue trigger; {"bindings": [{"type": "httpOutput", "direction": "in"}]} uses invalid "httpOutput" type with wrong direction.

3. Final Answer:

   {"bindings": [{"type": "httpTrigger", "direction": "in", "authLevel": "function", "methods": ["get"]}]} -> Option A

4. Quick Check:

   HTTP trigger binding = {"bindings": [{"type": "httpTrigger", "direction": "in", "authLevel": "function", "methods": ["get"]}]} [OK]

Hint: HTTP triggers use "httpTrigger" type with "in" direction [OK]

Common Mistakes:

• Confusing trigger type with output binding
• Using wrong direction for triggers
• Mixing trigger types like queue or timer

3. Given this Azure Function code snippet triggered by an HTTP request:

module.exports = async function (context, req) {
  context.log('Function started');
  context.res = { status: 200, body: 'Hello ' + (req.query.name || 'world') };
};

What will be the HTTP response body if the request URL is http://example.com/api?name=Alice?

medium

A. "Error: name not found"

B. "Hello world"

C. "Hello undefined"

D. "Hello Alice"

Solution

1. Step 1: Understand the code logic

   The function reads the query parameter "name" from the request. If "name" exists, it uses it; otherwise, it defaults to "world".

2. Step 2: Apply the input URL query

   The URL has "name=Alice", so the response body becomes "Hello Alice".

3. Final Answer:

   "Hello Alice" -> Option D

4. Quick Check:

   Query name present = "Hello Alice" [OK]

Hint: Check if query parameter exists; else use default [OK]

Common Mistakes:

• Ignoring query parameters
• Assuming default always used
• Confusing response body with error

4. You deployed an Azure Function with a timer trigger but it never runs. Which of these is the most likely cause?

medium

A. The schedule expression in function.json is incorrect

B. The function app is running and healthy

C. The HTTP trigger is missing

D. The function code has no output binding

Solution

1. Step 1: Check timer trigger configuration

   If the schedule expression is wrong, the timer never fires, so the function won't run.

2. Step 2: Evaluate other options

   Running app is good; missing HTTP trigger is irrelevant for timer trigger; output binding absence doesn't stop trigger execution.

3. Final Answer:

   The schedule expression in function.json is incorrect -> Option A

4. Quick Check:

   Wrong schedule = no timer run [OK]

Hint: Check cron schedule syntax for timer triggers [OK]

Common Mistakes:

• Confusing trigger types
• Ignoring schedule format errors
• Assuming output binding affects trigger

5. You want an Azure Function to process messages from a queue and then send results to a database without writing extra code to connect to the database. Which feature should you use to achieve this?

hard

A. Manually call the database API from the function

B. Use an output binding for the database

C. Use a timer trigger to poll the database

D. Write database connection code inside the function

Solution

1. Step 1: Understand output bindings

   Output bindings let functions send data to other services automatically without extra connection code.

2. Step 2: Match requirement to feature

   Using an output binding for the database allows sending results directly after processing queue messages.

3. Final Answer:

   Use an output binding for the database -> Option B

4. Quick Check:

   Output binding sends data without extra code [OK]

Hint: Output bindings connect services without manual code [OK]

Common Mistakes:

• Thinking manual code is always needed
• Confusing triggers with output bindings
• Using timer triggers incorrectly