ARM template parameters and variables in Azure - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of parameters in an ARM template?

Parameters allow you to pass values into the ARM template when deploying. They make the template flexible and reusable by letting you customize settings without changing the template code.

beginner

What are variables used for in an ARM template?

Variables store values that you want to reuse inside the template. They help avoid repeating the same value multiple times and can hold expressions or calculated values.

intermediate

Can you change the value of a variable during deployment in an ARM template?

No, variables are fixed once the template starts deploying. They are evaluated at deployment time but cannot be changed dynamically during deployment.

beginner

How do parameters improve the reusability of ARM templates?

By using parameters, you can deploy the same template with different values for each deployment, like different names or sizes, without editing the template itself.

intermediate

Give an example of when to use a variable instead of a parameter in an ARM template.

Use a variable when you want to create a value based on parameters or other variables, like combining a resource name prefix with a unique ID, so you don’t have to pass it every time.

What is the main difference between parameters and variables in an ARM template?

A Both are used to accept input during deployment.

B Variables accept input during deployment; parameters are set inside the template.

C Parameters accept input during deployment; variables are set inside the template.

D Both are fixed and cannot be changed.

Parameters accept input values when deploying the template, while variables are defined inside the template and cannot be changed during deployment.

Which ARM template element would you use to store a calculated value used multiple times?

A Output

B Parameter

C Resource

D Variable

Variables store calculated or repeated values inside the template for reuse.

Can you change a parameter value after deployment starts?

A No, parameters are fixed once deployment starts.

B Only for variables, not parameters.

C Only if you redeploy the template.

D Yes, anytime during deployment.

Parameters are set at deployment start and cannot be changed during deployment.

Why use parameters in ARM templates?

A To hardcode values inside the template.

B To allow customization without editing the template.

C To store temporary values during deployment.

D To output deployment results.

Parameters let you customize deployments by passing different values without changing the template.

Which of these is NOT a valid use of variables in ARM templates?

A Accepting user input during deployment.

B Holding a repeated value used multiple times.

C Storing a resource name built from parameters.

D Calculating a value based on other variables.

Variables cannot accept user input; only parameters do.

Explain the roles of parameters and variables in an ARM template and how they help in deployment.

Think about what you can change when you deploy versus what is fixed inside the template.

Describe a scenario where using a variable in an ARM template is better than using a parameter.

Consider when you want to create a value from other values instead of asking the user to provide it.