Type conversion functions in MATLAB - Step-by-Step Execution

Concept Flow - Type conversion functions

Start with variable

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Choose conversion function

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Apply function: e.g., double(), int32(), char()

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Variable changes type

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Use converted variable in code

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End

Start with a variable, pick a conversion function, apply it to change the variable's type, then use the new type in your code.

Execution Sample

MATLAB

a = '123';
b = double(a);
c = int32(b);

Convert a string '123' to its ASCII numeric codes, then convert those numbers to 32-bit integers.

Execution Table

Step	Code Line	Variable	Value	Type	Action
1	a = '123';	a	'123'	char array	Assign string to a
2	b = double(a);	b	[49 50 51]	double array	Convert chars to ASCII codes
3	c = int32(b);	c	[49 50 51]	int32 array	Convert double to int32
4	-	-	-	-	End of execution

💡 All lines executed, variables converted successfully

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
a	undefined	'123'	'123'	'123'	'123' (char array)
b	undefined	undefined	[49 50 51]	[49 50 51]	[49 50 51] (double array)
c	undefined	undefined	undefined	[49 50 51]	[49 50 51] (int32 array)

Key Moments - 2 Insights

Why does double('123') give numbers like 49, 50, 51 instead of 123?

Because double() converts each character to its ASCII code, so '1' becomes 49, '2' becomes 50, and '3' becomes 51, as shown in step 2 of the execution_table.

Does int32() change the numeric values when converting from double?

No, int32() changes the data type but keeps the numeric values the same, as seen in step 3 where values remain [49 50 51] but type changes to int32.

Visual Quiz - 3 Questions

Look at the execution_table, what is the type of variable b after step 2?

A char array

B int32 array

C double array

D string

💡 Hint

Check the 'Type' column for variable b at step 2 in the execution_table.

At which step does variable c get its value assigned?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at the 'Code Line' and 'Variable' columns in the execution_table to see when c is assigned.

If we replace double(a) with int8(a), what would be the type of b after step 2?

A int8 array

B double array

C char array

D int32 array

💡 Hint

int8() converts to 8-bit integers, so the type changes accordingly.

Concept Snapshot

Type conversion functions in MATLAB:
- Use functions like double(), int32(), char() to change variable types.
- double('abc') converts chars to ASCII codes.
- int32(doubleVar) changes numeric type without changing values.
- Useful to prepare data for different operations.

Full Transcript

This example shows how MATLAB converts types using functions. First, a string '123' is stored in variable a as a char array. Then, double(a) converts each character to its ASCII numeric code, resulting in b as a double array with values [49 50 51]. Next, int32(b) converts these double numbers to 32-bit integers, stored in c. The values remain the same but the type changes. This process helps when you need to work with numbers instead of characters or change numeric precision.