Scripting with variables and loops in Azure - Step-by-Step Execution

Process Flow - Scripting with variables and loops

Start Script

↓

Set Variable

↓

Check Loop Condition

↓

Execute Loop Body

↓

Update Variable

↩Back to Check Loop Condition

The script starts by setting a variable, then checks a loop condition. If true, it runs the loop body, updates the variable, and repeats until the condition is false.

Execution Sample

Azure

count=0
while [ $count -lt 3 ]; do
  echo "Count is $count"
  count=$((count + 1))
done

This script prints the count from 0 to 2 by increasing the variable in a loop.

Process Table

Step	Variable 'count'	Condition 'count < 3'	Action	Output
1	0	True	Print 'Count is 0'	Count is 0
2	1	True	Print 'Count is 1'	Count is 1
3	2	True	Print 'Count is 2'	Count is 2
4	3	False	Exit loop

💡 Loop ends because count reaches 3 and condition '3 < 3' is False

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
count	0	1	2	3	3

Key Moments - 2 Insights

Why does the loop stop when count is 3?

Because the condition 'count < 3' becomes False at step 4, so the loop exits as shown in the execution_table row 4.

What happens if we forget to update 'count' inside the loop?

The variable 'count' would stay the same, causing the condition to always be True and the loop to run forever, never reaching the exit shown in the execution_table.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of 'count' at step 2?

A 1

B 0

C 2

D 3

💡 Hint

Check the 'Variable count' column in execution_table row 2.

At which step does the loop condition become false?

A Step 3

B Step 4

C Step 2

D Step 1

💡 Hint

Look at the 'Condition' column in execution_table to find when it is False.

If we start 'count' at 1 instead of 0, how many times will the loop run?

A 1 time

B 3 times

C 2 times

D 4 times

💡 Hint

Refer to variable_tracker and execution_table logic for how count changes and loop condition.

Concept Snapshot

Scripting with variables and loops:
- Initialize a variable before the loop.
- Use a condition to control loop execution.
- Inside the loop, perform actions and update the variable.
- Loop stops when condition is false.
- Always update variables to avoid infinite loops.

Full Transcript

This visual execution shows a simple script using a variable and a loop. The variable 'count' starts at 0. The loop checks if 'count' is less than 3. If yes, it prints the count and increases it by 1. This repeats until 'count' reaches 3, then the loop stops. Key points include updating the variable inside the loop and understanding when the loop ends.