External Interfaces/API Reference    
mxGetFieldByNumber

Get a field value, given a field number and an index in a structure array

C Syntax

Arguments

array_ptr
   Pointer to a structure mxArray.

index
   The desired element. The first element of an mxArray has an index of 0, the second element has an index of 1, and the last element has an index of N-1, where N is the total number of elements in the structure mxArray. See mxCalcSingleSubscript for more details on calculating an index.

field_number
   The position of the field whose value you want to extract. The first field within each element has a field number of 0, the second field has a field number of 1, and so on. The last field has a field number of N-1, where N is the number of fields.

Returns

A pointer to the mxArray in the specified field for the desired element, on success. Returns NULL if passed an invalid argument or if there is no value assigned to the specified field. Common causes of failure include:

Description

Call mxGetFieldByNumber to get the value held in the specified field_number at the indexed element.

Calling

is equivalent to calling

where index is zero if you have a one-by-one structure.

Examples

See phonebook.c in the refbook subdirectory of the examples directory.

For additional examples, see mxisclass.c in the mx subdirectory of the examples directory and explore.c in the mex subdirectory of the examples directory.

See Also

mxGetField, mxGetFieldNameByNumber, mxGetFieldNumber, mxGetNumberOfFields, mxSetField, mxSetFieldByNumber


  mxGetField mxGetFieldNameByNumber