R Console and script files in R Programming - Step-by-Step Execution

Concept Flow - R Console and script files

Start R Console

↓

Type commands

↓

Commands execute immediately

↓

View output in console

↓

Write script file (.R)

↓

Save script

↓

Run script in console

↓

See script output in console

↓

Modify script and rerun

↓

End session or continue

This flow shows how you start the R console, type commands directly or run saved script files, and see output immediately.

Execution Sample

R Programming

x <- 5
print(x)
# Save this in script.R
# Run script with source('script.R')

Assign 5 to x, print x in console, save commands in a script file, then run the script to see output.

Execution Table

Step	Action	Input/Code	Console Output	Notes
1	Start R Console			R console is ready for commands
2	Type command	x <- 5		Assign 5 to variable x
3	Type command	print(x)	[1] 5	Print value of x
4	Write script file	script.R with x <- 5; print(x)		Save commands in a file
5	Run script	source('script.R')	[1] 5	Run script, output shown in console
6	Modify script	Change x <- 10		Update script file
7	Run script again	source('script.R')	[1] 10	See updated output
8	End session			Close R console or continue

💡 User ends session or stops running commands

Variable Tracker

Variable	Start	After Step 2	After Step 6	Final
x	undefined	5	10	10

Key Moments - 3 Insights

Why does typing commands in the console show output immediately?

Because the console executes each command as soon as you press Enter, as shown in steps 2 and 3 of the execution_table.

What is the difference between typing commands in the console and running a script file?

Typing commands runs them one by one immediately, while running a script file executes all commands saved in the file at once, as seen in steps 3 and 5.

How do changes in the script file affect the output when rerun?

Modifying the script changes variable values or commands, so when you run it again, the output updates accordingly, shown in steps 6 and 7.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of x after step 2?

A 5

B undefined

C 10

D 0

💡 Hint

Check the variable_tracker after Step 2 shows x = 5

At which step does the console show output '[1] 5'?

A Step 5

B Step 7

C Step 3

D Step 2

💡 Hint

Look at execution_table output column for Step 3

If you change x <- 10 in the script and rerun, what will be the output at step 7?

A [1] 5

B [1] 10

C No output

D Error

💡 Hint

See variable_tracker and execution_table steps 6 and 7 for updated value

Concept Snapshot

R Console lets you type commands and see results immediately.
Script files (.R) save commands to run later.
Use source('file.R') to run scripts in console.
Modify scripts and rerun to update output.
Console is interactive; scripts automate commands.

Full Transcript

This visual trace shows how the R console works alongside script files. You start the console and type commands like assigning a value to x and printing it. The console runs commands immediately and shows output. You can save commands in a script file with extension .R. Running the script with source('script.R') executes all commands inside and shows output in the console. Changing the script and rerunning updates the output. Variables like x change values as the script changes. This helps beginners see the difference between interactive console use and running saved scripts.