String comparison in MATLAB - Step-by-Step Execution

Concept Flow - String comparison

Start

↓

Input two strings

↓

Compare strings

↓

Are strings equal?

Yes→Output: true

↓

Output: false

↓

End

The program takes two strings, compares them, and outputs true if they are the same, otherwise false.

Execution Sample

MATLAB

str1 = 'hello';
str2 = 'Hello';
result = strcmp(str1, str2);

This code compares two strings 'hello' and 'Hello' and stores true or false in result.

Execution Table

Step	Action	Evaluation	Result
1	Assign str1	str1 = 'hello'	str1 = 'hello'
2	Assign str2	str2 = 'Hello'	str2 = 'Hello'
3	Compare str1 and str2 using strcmp	strcmp('hello', 'Hello')	0
4	Store result	result = 0	result = 0

💡 Comparison returns false because 'hello' and 'Hello' differ in case.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
str1	undefined	'hello'	'hello'	'hello'	'hello'
str2	undefined	undefined	'Hello'	'Hello'	'Hello'
result	undefined	undefined	undefined	0	0

Key Moments - 2 Insights

Why does strcmp return false even though the words look similar?

Because strcmp is case-sensitive, it treats 'hello' and 'Hello' as different strings (see execution_table step 3).

What if we want to compare strings ignoring case?

Use strcmpi instead of strcmp to ignore case differences (not shown here but important to know).

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the result of strcmp('hello', 'Hello')?

A error

B true

C false

D undefined

💡 Hint

Check the 'Result' column in execution_table row for step 3.

At which step is the variable 'result' assigned a value?

A Step 4

B Step 2

C Step 1

D Step 3

💡 Hint

Look at the 'Action' column for when 'result' is stored.

If str2 was changed to 'hello' (all lowercase), what would strcmp return at step 3?

A false

B true

C error

D undefined

💡 Hint

strcmp returns true only if strings are exactly the same (see variable_tracker for str1 and str2 values).

Concept Snapshot

String comparison in MATLAB:
- Use strcmp(str1, str2) to check if two strings are exactly equal.
- strcmp is case-sensitive.
- Returns logical true (1) if equal, false (0) if not.
- Use strcmpi to ignore case differences.
- Result can be stored in a variable for further use.

Full Transcript

This example shows how MATLAB compares two strings using strcmp. First, two strings are assigned to variables str1 and str2. Then strcmp compares them character by character, considering case. Since 'hello' and 'Hello' differ in case, strcmp returns false. The result is stored in the variable result. Beginners often confuse case sensitivity, so remember strcmp treats uppercase and lowercase letters as different. To ignore case, use strcmpi. This trace helps visualize each step and variable change during string comparison.