Workspace and variable management in MATLAB - Step-by-Step Execution

Concept Flow - Workspace and variable management

Start MATLAB session

↓

Create variables

↓

Variables stored in Workspace

↓

Use variables in commands/functions

↓

Modify or clear variables

↓

Workspace updated

↓

End or save session

This flow shows how variables are created, stored, used, modified, and cleared in the MATLAB workspace during a session.

Execution Sample

MATLAB

a = 5;
b = 10;
c = a + b;
clear a;
disp(who);

This code creates variables a, b, c, clears a, and then displays remaining variables in the workspace.

Execution Table

Step	Command	Workspace Variables	Action	Output
1	a = 5;	a	Create variable a with value 5
2	b = 10;	a, b	Create variable b with value 10
3	c = a + b;	a, b, c	Create c as sum of a and b (15)
4	clear a;	b, c	Remove variable a from workspace
5	disp(who);	b, c	Display variables currently in workspace	b c

💡 End of commands; workspace contains variables b and c only.

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	Final
a	undefined	5	5	5	cleared	cleared
b	undefined	undefined	10	10	10	10
c	undefined	undefined	undefined	15	15	15

Key Moments - 2 Insights

Why does variable 'a' disappear after the 'clear a;' command?

The 'clear a;' command removes 'a' from the workspace, so it no longer exists after step 4, as shown in the execution_table row 4.

What does the 'who' function show after clearing 'a'?

The 'who' function lists all variables currently in the workspace. After clearing 'a', it shows only 'b' and 'c' as in execution_table row 5.

Visual Quiz - 3 Questions

Look at the execution_table at step 3. What is the value of variable 'c'?

A 5

B 15

C 10

D undefined

💡 Hint

Check the 'Workspace Variables' and 'Action' columns at step 3 in the execution_table.

At which step does variable 'a' get removed from the workspace?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at the 'Command' and 'Workspace Variables' columns in the execution_table.

If we did not run 'clear a;', what would 'who' display at step 5?

A a, b, c

B b, c

C a, c

D a, b

💡 Hint

Compare the workspace variables before and after the 'clear a;' command in the execution_table.

Concept Snapshot

Workspace and variable management in MATLAB:
- Variables are created by assignment (e.g., a = 5;).
- Variables live in the workspace until cleared or session ends.
- Use 'clear varname;' to remove variables.
- Use 'who' to list current workspace variables.
- Variables can be used and modified anytime during the session.

Full Transcript

This lesson shows how MATLAB manages variables in its workspace. When you assign a value to a variable, it appears in the workspace. You can use these variables in calculations or commands. If you want to remove a variable, use the 'clear' command with the variable name. The 'who' command lists all variables currently stored. This helps you keep track of what data you have while working. The example code creates three variables, clears one, and then shows the remaining variables. This process helps you manage your workspace efficiently.