---
layout: doc
title: arrays / map_array
---
# map_array

### NAME

    map_array() - modify an array of elements via application of a function

### SYNOPSIS

    mixed *map_array( mixed *arr, string fun, object ob,
                      mixed extra, ... );
    mixed *map_array( mixed *arr, function f, mixed extra, ... );

### DESCRIPTION

    Returns  an  array  holding  the  items  of 'arr' mapped through either
    'ob->fun()' or 'f'.  The function is called for each element  in  'arr'
    with that element as a parameter. A second parameter 'extra' is sent in
    each call if given.  Principal function:

        foreach (index) arr[index] = ob->fun(arr[index],extra);

    The value returned by 'ob->fun(arr[.index.], extra)' replaces the existing
    element in the array. If 'arr' is not an array, then 0 will be returned.

### SEE ALSO

    filter(3), map(3), sort_array(3), unique_array(3)

