entries - Key-value pairs of dictionary - MATLAB (original) (raw)

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Key-value pairs of dictionary

Since R2022b

Syntax

Description

`E` = entries([d](#mw%5F820daf04-84cc-4e51-84ca-ac2dc2d5b1e1%5Fsep%5Fmw%5F6b2c4725-2753-4b6a-805b-39686bdc1868)) returns a table containing the key-value pairs of the specified dictionary. Entries are returned in the order in which the entries were added to the dictionary.

example

`E` = entries([d](#mw%5F820daf04-84cc-4e51-84ca-ac2dc2d5b1e1%5Fsep%5Fmw%5F6b2c4725-2753-4b6a-805b-39686bdc1868),[format](#mw%5F17e62208-304f-434f-b01c-985fc37566a0))specifies the output format as a table or a structure. For example,entries(d,"struct") returns a structure containing the key-value pairs of d. Use this option for data types that are not compatible with tables.

example

Examples

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Create a dictionary containing several key-value pairs.

names = ["Unicycle" "Bicycle" "Tricyle"]; wheels = [1 2 3]; d = dictionary(wheels,names)

d =

dictionary (double ⟼ string) with 3 entries:

1 ⟼ "Unicycle"
2 ⟼ "Bicycle"
3 ⟼ "Tricyle"

Use entries to return a table containing the entries stored in d.

E=3×2 table Key Value
___ __________

 1     "Unicycle"
 2     "Bicycle" 
 3     "Tricyle"

Create a dictionary containing several key-value pairs.

names = ["Unicycle" "Bicycle" "Tricyle"]; wheels = [1 2 3]; d = dictionary(wheels,names)

d =

dictionary (double ⟼ string) with 3 entries:

1 ⟼ "Unicycle"
2 ⟼ "Bicycle"
3 ⟼ "Tricyle"

Use entries and specify the output format as "struct" to return a struct array containing the entries stored in d.

E=3×1 struct array with fields: Key Value

Input Arguments

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Dictionary, specified as a dictionary object. If d is unconfigured, entries throws an error.

Output format, specified as one of these values:

"table" — Return key-value pairs in a table. This format is the default output format.
"struct" — Return an n-by-1 struct array, where each of the n struct elements has the fields key andvalue corresponding to each of the n entries in the specified dictionary. Use this option for data types that are not compatible with tables.
"cell" — Return key-value pairs in an-by-2 cell array where n is the number of entries, the first column contains keys, and the second column contains values.

Extended Capabilities

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Usage notes and limitations:

The format argument must be constant.
If the format argument is "table", the dictionary cannot be empty at runtime. Dictionary keys and values must be numeric types, character arrays, structures, cell arrays, or enumerations.
If the format argument is "cell", all keys and values must have the same type.
The code generator does not treat a dictionary as a constant, even if the dictionary is constant at code generation time. This means that theentries function does not return constants. You cannot pass the output of the entries function to a function that requires constant inputs. You cannot use the output of the entries function for operations that require constants, such as indexing into a heterogeneous cell array. The code generator also cannot perform optimizations that depend on constants, such as constant folding, on the output of the entries function.

For additional considerations that apply when generating C/C++ code for MATLAB® dictionaries, see Dictionary Limitations for Code Generation (MATLAB Coder).

Version History

Introduced in R2022b

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You can generate C/C++ code for the dictionary entries function.