<?php

	$bancos = array(
	    array('code' => '001', 'name' => 'Banco do Brasil'),
	    array('code' => '003', 'name' => 'Banco da Amazônia'),
	    array('code' => '004', 'name' => 'Banco do Nordeste'),
	    array('code' => '021', 'name' => 'Banestes'),
	    array('code' => '025', 'name' => 'Banco Alfa'),
	    array('code' => '027', 'name' => 'Besc'),
	    array('code' => '029', 'name' => 'Banerj'),
	    array('code' => '031', 'name' => 'Banco Beg'),
	    array('code' => '033', 'name' => 'Banco Santander Banespa')
	);
	
    echo BancoPorID( '001' ) . PHP_EOL;
    echo BancoPorID( '033' ) . PHP_EOL;
    echo BancoPorID( '027' ) . PHP_EOL;

    function BancoPorID($id) {
	   global $bancos;
	   $key = array_search( $id, array_column( $bancos, 'code') );
	   return $key !== false ? $bancos[$key]['name'] : 'Banco desconhecido';
	}