types

Types of dictionary keys and values

Since R2022b

Syntax

[keyType,valueType] = types(d)

keyType = types(d)

Description

[keyType,valueType] = types(d) returns the data types of keys and values of the specified dictionary. If d is an unconfigured dictionary, then types returns a <missing> string scalar.

keyType = types(d) returns the data types of keys.

Examples

Query Types of Dictionary Keys and Values

Create a dictionary containing three key-value pairs that map numbers to strings.

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

d =

  dictionary (double --> string) with 3 entries:

    1 --> "Unicycle"
    2 --> "Bicycle"
    3 --> "Tricycle"

Use types to return the types for the keys and values of the dictionary.

[keyType,valueType] = types(d)

keyType = 
"double"

valueType = 
"string"

Input Arguments

d — Dictionary

dictionary object

Dictionary, specified as a dictionary object.

Output Arguments

keyType — Data type of dictionary keys

string scalar

Data type of dictionary keys, returned as a string scalar.

valueType — Value data type

string scalar

Value data type, returned as a string scalar.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Code generation does not support calling the types function on an unconfigured dictionary.

• The code generator does not treat a dictionary as a constant, even if the dictionary is constant at code generation time. This means that the types function does not return a constant. You cannot pass the output of the types function to a function that requires constant inputs. You cannot use the output of the types 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 types 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

R2024b: Code generation support

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