numEntries

Number of key-value pairs in dictionary

Since R2022b

Syntax

n = numEntries(d)

Description

n = numEntries(d) returns the number of key-value pairs stored in the specified dictionary. If d is an unconfigured dictionary, then numEntries returns 0.

Examples

Determine Number of Entries in Dictionary

Create a dictionary containing several key-value pairs.

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 numEntries to determine how many key-value pairs are stored in d.

n = numEntries(d)

n = 
3

Input Arguments

d — Dictionary

dictionary object

Dictionary, specified as a dictionary object.

Extended Capabilities

C/C++ Code Generation

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

Usage notes and limitations:

• 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 numEntries function does not return a constant. You cannot pass the output of the numEntries function to a function that requires constant inputs. You cannot use the output of the numEntries 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 numEntries 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 numEntries function.