Why conditionals branch script logic in Bash Scripting - Visual Breakdown

Concept Flow - Why conditionals branch script logic

Start script

↓

Evaluate condition

↓

Run True

↓

Continue script

↓

End

The script starts by checking a condition. If true, it runs one set of commands; if false, it runs another. Then it continues.

Execution Sample

Bash Scripting

if [ "$age" -ge 18 ]; then
  echo "Adult"
else
  echo "Minor"
fi

This script checks if age is 18 or more, prints 'Adult' if yes, otherwise 'Minor'.

Execution Table

Step	Condition	Result	Branch Taken	Output
1	[ "$age" -ge 18 ]	True	Then branch	Adult
2	End of if	-	-	-

💡 Condition became true, so 'Then' branch ran and script continued after if.

Variable Tracker

Variable	Start	After Step 1	Final
age	20	20	20

Key Moments - 2 Insights

Why does the script run only one branch, not both?

Because the condition decides which branch runs. See execution_table step 1: only the 'Then' branch runs when condition is true.

What happens if the condition is false?

The script runs the 'else' branch instead. This is shown by the branching in concept_flow where false leads to a different path.

Visual Quiz - 3 Questions

Look at the execution_table, what output is printed when the condition is true?

A No output

B Adult

C Minor

D Error message

💡 Hint

Check the Output column in execution_table row 1 where condition is true.

At which step does the script decide which branch to run?

A Step 2

B Before Step 1

C Step 1

D After Step 2

💡 Hint

Look at the Condition and Branch Taken columns in execution_table row 1.

If age was 16, which branch would run?

A Else branch

B Then branch

C Both branches

D No branch

💡 Hint

Refer to concept_flow where false condition leads to else branch.

Concept Snapshot

if [ condition ]; then
  # commands if true
else
  # commands if false
fi

- Condition decides which commands run
- Only one branch runs per check
- Helps script choose actions based on data

Full Transcript

This script uses a conditional to decide what to do next. It checks if the variable age is 18 or more. If yes, it prints 'Adult'. If not, it prints 'Minor'. The condition acts like a fork in the road, sending the script down one path or the other. This way, the script can make choices and behave differently depending on the data it sees.