PHP Form Field Mapping Replacement

PHP_Form_Field_Mapping_Replacement.php

<?php

$search_by_keys = array(
  'foo',
  'bar',
  'baz'
);

$replace_with_keys = array(
  'meow',
  'rawr',
  'ruff'
);

$original_form_fields_with_values = array(
  'foo'=>'value',
  'bar'=>'value',
  'baz'=>'value'
);

$new_form_fields_with_values = array();

// Iterate over all form fields to build a new form key=>value object
foreach( $original_form_fields_with_values as $original_key => $value ) {

  // See if one of our field mappings needs to be applied
  if ( in_array( $original_key, $search_by_keys ) ) {
      
      // Find out which replacement we need to use by finding the array position
      $replacement_index = array_search( $original_key, $search_by_keys );
      
      // Get the key with the replacement field name
      $replacement_fieldname = $replace_with_keys[ $replacement_index ];

      // Put the corrected fieldname in the new form key=>value array
      $new_form_fields_with_values[ $replacement_fieldname ] = $value;

  } else {

    // No Op copy field=>value form data
    $new_form_fields_with_values[ $original_key ] = $value;

  }
  
}

var_dump( $new_form_fields_with_values );

What about this:

<?php
$replace = array(
  'foo' => 'meow',
  'bar' => 'rawr',
  'baz' => 'ruff'
);
$original_form_fields_with_values = array(
  'foo'=>'value',
  'bar'=>'value',
  'baz'=>'value'
);

$new_form_fields_with_values = array();
foreach( $original_form_fields_with_values as $key => $value ) {
  if ($original_form_fields_with_values[$replace[$key]]) {
    $new_form_fields_with_values[$replace[$key]] = $value;
  } else {
    $new_form_fields_with_values[$key] = $value;
  }
}
var_dump( $new_form_fields_with_values );

<?php
$replace = array(
  'foo' => 'meow',
  'bar' => 'rawr',
  'baz' => 'ruff',
  'wat' => 'nunu',
);
$original_form_fields_with_values = array(
  'foo'=>'value',
  'bar'=>'value',
  'baz'=>'value',
  'hehe' => 'blaine',
);

$new_form_fields_with_values = array();
foreach( $original_form_fields_with_values as $key => $value ) {
  if ($replace[$key]) {
    $new_form_fields_with_values[$replace[$key]] = $value;
  } else {
    $new_form_fields_with_values[$key] = $value;
  }
}
var_dump( $new_form_fields_with_values );