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getfield - Field of structure array

Syntax

value = getfield(struct, 'field') value = getfield(struct,{sIndx1,...,sIndxM},'field',{fIndx1,...,fIndxN})

Description

value = getfield(struct, 'field'), where struct is a 1-by-1 structure, returns the contents of the specified field, equivalent to value = struct.field. Pass field references as strings.

value = getfield(struct,{sIndx1,...,sIndxM},'field',{fIndx1,...,fIndxN}) returns the contents of the specified field, equivalent to value = struct(sIndx1,...,sIndxM).field(fIndx1,...,fIndxN). The getfield function supports multiple sets of field and fIndx inputs, and all Indx inputs are optional. If structure struct or any of the fields is a nonscalar structure, and you do not specify an Indx, the getfield function returns the values associated with the first index. If you specify a single colon operator for an fIndx input, enclose it in single quotation marks: ':'.

Tips

For most cases, retrieve data from a structure array by indexing rather than using the getfield function. For more information, see Returning Data from a Struct Array and Creating Field Names Dynamically.
Call getfield to simplify references to structure arrays with nested fields, or to avoid creating unnecessary temporary variables, as shown in the Examples section.

Examples

The what function returns a structure array that describes the MATLAB files in the current folder. Find the files with the .m extension:

files = getfield(what, 'm');

To perform the same task by indexing requires that you create a temporary variable:

templist = what;
files = templist.m;

Find values within a structure that contains nested fields:

level = 5;
semester = 'Fall';
subject = 'Math';
student = 'John_Doe';
fieldnames = {semester subject student};

% Add data to a structure named grades.
grades(level).(semester).(subject).(student)(10,21:30) = ...
             [85, 89, 76, 93, 85, 91, 68, 84, 95, 73];

% Retrieve the data added.
getfield(grades, {level}, fieldnames{:}, {10,21:30})

Using the structure defined in the previous example, find all values in the tenth row of the specified field:

getfield(grades, {level}, fieldnames{:}, {10,':'})

How To

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