Type checking (class, isa) in MATLAB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if variable x is of class 'double'.

MATLAB

if [1](x, 'double')
    disp('x is a double');
end

Drag options to blanks, or click blank then click option'

Aisa

Btype

Cclass

Disclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' instead of 'isa' to check type.

The isa function checks if a variable is of a specified class.

2fill in blank

medium

Complete the code to get the class name of variable y.

MATLAB

typeName = [1](y);

Drag options to blanks, or click blank then click option'

Atype

Bclass

Ctypeof

Disa

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'isa' instead of 'class' to get the class name.

The class function returns the class name of a variable as a string.

3fill in blank

hard

Fix the error in the code to check if z is a cell array.

MATLAB

if [1](z, 'cell')
    disp('z is a cell array');
end

Drag options to blanks, or click blank then click option'

Aclass

Bisclass

Cisa

Dtype

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' instead of 'isa' for type checking.

To check if a variable is a cell array, use isa with 'cell'.

4fill in blank

hard

Fill both blanks to create a dictionary of variable names and their classes for variables in the list.

MATLAB

vars = {'a', 'b', 'c'};
classes = containers.Map();
for i = 1:length(vars)
    varName = vars{i};
    classes(varName) = [1](eval([2]));
end

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Aclass

BvarName

Cisa

Dvars{i}

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'isa' instead of 'class' for getting class name.

Using 'vars{i}' instead of 'varName'.

Use class to get the class name of the variable whose name is stored in varName.

5fill in blank

hard

Fill all three blanks to check if each variable in the list is of class 'double' and store the result in a logical array.

MATLAB

vars = {x, y, z};
isDouble = false(1, length(vars));
for k = 1:length(vars)
    isDouble(k) = [1](vars[2], '[3]');
end

Drag options to blanks, or click blank then click option'

Aisa

B{k}

Cdouble

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' instead of 'isa' for checking type.

Using wrong indexing syntax.

Use isa to check if each variable is 'double'. The variable is accessed as vars{k}.