mxGetFieldNameByNumber (External Interfaces/API Reference)

Get a field name, given a field number in a structure array

Fortran Syntax

character*(*) function mxGetFieldNameByNumber(pm, fieldnumber)
integer*4 pm, fieldnumber

Arguments

pm
Pointer to a structure mxArray.

fieldnumber
The position of the desired field. For instance, to get the name of the first field, set fieldnumber to 1; to get the name of the second field, set fieldnumber to 2; and so on.

Returns

The nth field name, on success. Returns 0 on failure. Common causes of failure include:

Specifying a pm that does not point to a structure mxArray. Call mxIsStruct to determine if pm points to a structure mxArray.

Specifying a value of fieldnumber greater than the number of fields in the structure mxArray. (Remember that fieldnumber 1 represents the first field, so index N represents the last field.)

Description

Call mxGetFieldNameByNumber to get the name of a field in the given structure mxArray. A typical use of mxGetFieldNameByNumber is to call it inside a loop to get the names of all the fields in a given mxArray.

Consider a MATLAB structure initialized to

patient.name = 'John Doe';
patient.billing = 127.00;
patient.test = [79 75 73; 180 178 177.5; 220 210 205];

The fieldnumber 1 represents the field name name; fieldnumber 2 represents field name billing; fieldnumber 3 represents field name test. A fieldnumber other than 1, 2, or 3 causes mxGetFieldNameByNumber to return 0.

mxGetFieldByNumber mxGetFieldNumber