Script files and editor in MATLAB - Step-by-Step Execution

Concept Flow - Script files and editor

Open Editor

↓

Write Script Code

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Save as .m file

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Run Script

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View Output in Command Window

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Edit and Repeat if needed

This flow shows how you open the editor, write and save a script file, run it, and see the output.

Execution Sample

MATLAB

a = 5;
b = 3;
c = a + b;
disp(c);

This script adds two numbers and displays the result.

Execution Table

Step	Code Line	Action	Variable State	Output
1	a = 5;	Assign 5 to a	a=5
2	b = 3;	Assign 3 to b	a=5, b=3
3	c = a + b;	Add a and b, assign to c	a=5, b=3, c=8
4	disp(c);	Display value of c	a=5, b=3, c=8	8
5	End of script	Script finishes running	a=5, b=3, c=8

💡 Script ends after last line is executed.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
a	undefined	5	5	5	5
b	undefined	undefined	3	3	3
c	undefined	undefined	undefined	8	8

Key Moments - 2 Insights

Why does the output only show after disp(c) and not after assigning c = a + b?

Because MATLAB only shows output when you explicitly ask it to display, like with disp(). Assignments do not print values automatically (see execution_table step 3 vs step 4).

What happens if you forget to save the script before running?

The editor will run the last saved version, so changes not saved won't run. Always save your .m file before running (concept_flow step 3).

Visual Quiz - 3 Questions

Look at the execution table, what is the value of variable 'c' after step 3?

A 8

B 5

C 3

D undefined

💡 Hint

Check the 'Variable State' column in row for step 3.

At which step does the script display output to the command window?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look for the 'Output' column showing a value.

If you change 'disp(c);' to 'disp(a);', what will be displayed at step 4?

A 3

B 8

C 5

D Error

💡 Hint

Refer to variable_tracker for value of 'a' after step 1.

Concept Snapshot

Script files in MATLAB are saved as .m files.
Use the Editor to write and save your code.
Run scripts to execute all lines in order.
Use disp() to show output in Command Window.
Save changes before running to see updates.

Full Transcript

In MATLAB, you write code in the Editor and save it as a script file with a .m extension. When you run the script, MATLAB executes each line in order. Variables get assigned values step by step. To see output, you use the disp() function. The Editor helps you write, save, and run scripts easily. Remember to save your script before running it so your latest changes take effect.