Structure arrays in MATLAB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a structure array in MATLAB?

A structure array is a data type that groups related data using named fields. Each element in the array can have the same fields but different values.

beginner

How do you create a structure array with fields 'Name' and 'Age' for two people?

Use the syntax: <br> s(1).Name = 'Alice'; s(1).Age = 30;<br> s(2).Name = 'Bob'; s(2).Age = 25;

beginner

How do you access the 'Age' of the second element in a structure array s?

Use s(2).Age to get the age of the second element.

intermediate

Can structure arrays have fields that are themselves arrays or other structures?

Yes, fields in a structure array can hold any data type, including arrays, other structures, or even function handles.

intermediate

How do you add a new field 'Height' to all elements of an existing structure array s?

You can add a new field by assigning it to each element, for example:<br> [s.Height] = deal(170);<br> This sets the 'Height' field to 170 for all elements.

What does s(3).Name represent in a structure array s?

A The 'Name' field of the third element in s

B The third character of the string in s.Name

C The third element of the field 'Name' in s

D The number of elements in s

s(3).Name accesses the 'Name' field of the third element in the structure array s.

How do you initialize an empty structure array with fields 'Name' and 'Age'?

A s = struct('Name', {}, 'Age', {});

B s = struct('Name', [], 'Age', []);

C s = [];

D s = struct();

Using struct with empty cell arrays for fields creates an empty structure array with specified fields.

Which command adds a field 'City' with value 'NY' to the first element of s?

A s.City(1) = 'NY';

B s.City = {'NY'};

C addfield(s, 'City', 'NY');

D s(1).City = 'NY';

Assigning s(1).City = 'NY' adds the field 'City' to the first element.

If s is a structure array, what does [s.Age] return?

A An error because fields cannot be concatenated

B The 'Age' field of the first element only

C An array of all 'Age' values from each element in s

D A cell array of 'Age' values

Using [s.Age] concatenates the 'Age' values from all elements into a numeric array.

Can structure arrays in MATLAB store different data types in different fields?

A No, all fields must have the same data type

B Yes, each field can hold different data types

C Only numeric types are allowed

D Only strings are allowed

Structure fields can hold any data type independently.

Explain how to create and access elements in a structure array in MATLAB.

Think about how you store and get data like a contact list.

Describe how to add a new field to all elements of an existing structure array.

Imagine adding a new column to a table for everyone.